Changes since 0.1.0

1. src/xfig/plot.sl: modified major/minor axis routines to better deal
   with tic marks that span many orders of magnitude for log plots.
2. src/xfig/plot.sl: If a log-axis does not include a point 10^n, then
   use linear tics-marks.
3. src/xfig/plot.sl: Allow major/minor tic positions to be specified.
4. src/xfig/core.sl: Changed the way the colors are indexed to allow
   and allow colors to be specified by index.
5. src/xfig/polyline.sl: pict_scale was using the wrong object.
6. src/xfig/plot.sl: Use \times instead of \cdot for labels in the alt format
7. src/xfig/plot.sl: If a sym qualifier is given, do not draw lines unless
   line is also specified.
8. src/xfig/plot.sl: hplot method added for plotting histograms.
9. src/xfig/plot.sl: get_*_depth functions included a depth argument
10. src/xfig/plot.sl: Avoid the use of (@Array_Type) to create an array.
11. src/xfig/core.sl: Added orange, orange2-4 colors.
12. src/xfig/core.sl: All objects get set_pen_color, set_area_fill,
    set_thickness, set_lines_style, and set_fill_color methods.
13. src/xfig/objects.sl: Added qualifier support to a few functions.
14. src/xfig/polyline.sl: Added "just" qualifier to the xfig_new_pict
    function to specify its local coordinate system origin.
15. src/xfig/ellipse.sl: Fixed some bugs that surfaced when porting
    old code to use this version of xfig.
16. src/xfig/latex.sl: Added qualifier support to allow the "just"
    qualifier to propagate into the xfig_new_pict function.
17. examples/plot.sl: Tweaked some of the examples
18. src/xfig/plot.sl: plot_symbols now uses a polyline_list instead of
    individual polylines.  This makes it run faster when many points
    are involved.
19. src/xfig/core.sl: If an integer is passed to xfig_lookup_color,
    the value returned will be modulo num_colors.
20. src/xfig/polyline.sl: Use xfig_lookup_color in set_color methods.
21. src/xfig/plot.sl: Added "star", "larr", "rarr", "uarr", and "darr"
    symbols.  Also added xfig_plot_get_symbol_names functions.
22. examples/plot/symbol.sl: Rewrote this example.
23. src/vector.c: Modified the "vector" function to avoid an extra
    function when converting numeric value to a double.
24. src/xfig/polyline.sl: Tweaked the polyline_list_bbox method to
    improve performance.
25. src/xfig/plot.sl: added areafill and fillcolor qualifiers to the
    xfig_new_legend function.
26. src/xfig/polyline.sl: pict_scale was not accounting for the
    absolute position of the pict.
27. src/xfig/plot.sl: Added support for plotting via mixed world
    systems, e.g., world12, world21, etc.  Also, world0 may be used to
    refer to device coordinates, which run from 0 to 1.
28. src/xfig/plot.sl: The hplot method will call the shaded histogram
    routine if a fill qualifier is given.
29. examples/plot/world.sl: A new example.  Also some other examples
    were updated.
30. src/xfig/plot.sl: Added shade_region method and updated the
    world.sl example to illustrate its use.
31. src/xfig/plot.sl: When placing the title, account for the x2label.
32. src/xfig/plot.sl: Ignore tic_linestyle qualifier unless gridding.
33. src/xfig/plot.sl: Cleaned up the tic labeling code and added some
    minor tic labels when using log scaling.
34. src/vector.sl: small optimizations
35. src/xfig/clip.sl: Use slang2.2.0 list_to_array.
36. src/xfig/core.sl: Inline the vector calls in intersect_focal_plane.
37. src/xfig/plot.sl: Rewrote the way custom world coordinate systems
    were handled.  I also added a "cdf" system that is designed for
    plots of cumulative distribution functions.
38. src/xfig/*.sl: Replaced calls to system by calls to system_intr.
39. src/xfig/core.sl: Added an entry for .pdf to the device table.
40. src/xfig/latex.sl: Rewrote the cache code to use an assoc array.
41. src/xfig/plot.sl: Added format=val qualifier to axis method
42. src/xfig/plot.sl: Invalid index error in plot_shaded_histogram
43. src/xfig/plot.sl: Added sqrt plot transform
44. src/xfig/latex.sl: Added xfig_get/set_latex_preamble for adding
    additional elements to the preamble.
45. A preamble=value qualifier added to the latex functions to add
    additional lines to the latex preamble.
46. src/xfig/plot.sl: Added xfig_plot_get/set_default_size functions
    for setting the default plot sizes (w=14, h=10 are the defaults).
47. src/xfig/core.sl: Added "gray" color.
48. src/xfig/core.sl: rewrote Eye code to allow for a "roll".
49. src/xfig/core.sl: Modified the way the roll was implemented.
50. src/xfig/*.sl: Added a number of changes from Manfred Hanke.
51. src/xfig/core.sl: Defer the color lookups by the container objects
    to the objects themselves.
52. doc/*: Updated docs.
53. src/gcontour.sl: Remove unused code and fix a typo involving a
    reference to a local variable. (Manfred Hanke)
54. src/xfig/plot.sl: New function: xfig_multiplot, which may be used
    to conveniently stack plot objects on top of one another. (Manfred
    Hanke).
55. examples/plot/multiplot.sl: New example provided by Manfred Hanke.
56. examples/plot/image.sl: Use xfig_meshgrid instead of maplib function
    (Manfred Hanke).
57. src/xfig/polyline.sl: Allow xfig_new_polyline to accept a structure
    mimicking a Vector_Type object. (Manfred Hanke).
58. src/xfig/plot.sl: Added support for asymmetric error bars.  Also
    error bars for histograms are added at the center of the bin.
    (Manfred Hanke).
59. src/Makefile.in: Changes made to have the value of the
    _xfig_version_string track the changes.txt file.
60. src/xfig/plot.sl: The "ticlabels" qualifier to the plot functions may
    be used to specify user-defined labels.  See the
    examples/plot/ticlabels.sl for examples.  (Manfred Hanke).
61. src/xfig/plot.sl: Added a get_world method to the plot object:

         w = xfig_plot_new ();
	   .
	   .
	 world = w.get_world();  % ==> xmin=world[0], xmax=world[1],...

62. src/xfig/core.sl: Adjusted the order of plotting colors.  Also
    added "colors" example, which shows the colors.
63. src/xfig/core.sl: Added xfig_set_verbose and a new function called
    _xfig_check_help which handles the "help" qualifier.
64. src/xfig/polyline.sl: Added qualifier support to xfig_create_arrow
    for various arrow types (Manfred Hanke).
65. src/xfig/plot.sl: Numerous doc updates, and added support for a
    "help" qualifier (Manfred Hanke).
66. doc/: documentation updates (requires very recent version of
    tmexpand) (Manfred Hanke)
67. src/xfig/plot.sl: When creating tic labels in scientific notation,
    use the same exponent.
68. src/xfig/clip.sl: clips involving infinite values were not always
    being handled properly.
69. examples/plot/*.sl: removed dependence upon gsl.
70. merged a number of changes from Manfred Hanke (see git log for
    details):
       * documentation updates
       * Additional examples
       * added src/test/*
       * latex.sl: graphicx added to package latex package list,
	 xfig_set_latex_verbosity function, ...
       * plot.sl: fixes to the plot_scale method. depth qualifiers for
	 error bars, etc,
71. xfig/latex.sl: Changed the way verbose is handled.  Also if latex
    fails, run it again in interactive mode so that the error message
    gets displayed.
72. src/tests/: Renamed and modified the test scripts.
73. src/xfig/plot.sl: Pass qualifiers to _xfig_check_help.
74. src/*: Merged a number of changes from Manfred Hanke, including:

      Documentation updates
      Misc bugs fixes
      Updated examples
      Some code simplifications

    To see the details, use `git diff 9bacc1f..8595a99`.
75. src/xfig/plot.sl: The "depth" qualifier may be a reference to a
    variable, which if NULL, will be set upon return to the depth used:

       depth = NULL;
       w.plot (x1, y1; depth=&depth);
       w.plot (x2, y2; depth=depth-1);
76. src/xfig/latex.sl: If latex fails, run again with verbose=1.
77. examples/: Added pict/ and draw/ examples.
78. src/xfig.sl: Obsolete text.sl is nolonger loaded.
79. src/xfig/core.sl,latex.sl: tmpfile functions moved to core.sl
80. src/xfig/core.sl: added xfig_add_tmp_file, which will schedule a
    file for deletion at exit.  The ;delete qualifier to
    xfig_make_tmp_file will also do this.
81. src/plot.sl: Tweak ticlabels when min/max axis limits are nearly
    equal.
82. examples/plot/overlay.sl: img1 and img2 were not always the same
    size.
83. src/plot.sl: Modified change #81.
84. src/xfig/polyline.sl: Avoid writing really long lines to the
    output file.
85. Various updated from Manfred Hanke:
   * ticlabels in a plot respect default font style; font-related docs updated
   * xfig_plot.plot_png accepts arrays and produces pngs automatically
   * new .justify method; xfig_justify_object can work relative to other objects
   * colors can be specified as "#RRGGBB" with 6 hex-digits for RGB
   * A histogram plot's x-array may now also contain the last bin's 
     upper limit, if it has one element more than the y-array of the
     histogram data.
86. src/xfig/plot.sl: positioning bug-fix in xfig_multiplot (Manfred Hanke).
87. src/xfig/core.sl: #85 introduced a bug in the hbox/vbox functions
    (Manfred Hanke).
88. src/xfig/plot.sl: Change 67 introduced duplicate tic marks for grids running
    from, e.g, 0 to 30000.
89. src/xfig/plot.sl: Remove NaNs and Infs when determining the axis
    limits from the data.
90. merged Manfred's changes:
      - some documentation updates
      - unification of all examples' Makefiles
      - simplification of some plot-axes related code
        and improved support for axis bounding boxes
      - plots can include Xfig arrows
      - filled plot symbols do not require explicit area fill style = 20
      - plots support depth qualifier for pngs / picts
91. src/xfig/plot.sl: tweaked the axis bbox code to fix a bbox problem in
    #90.
92. src/xfig/plot.sl: silly error introduced by #91 fixed (Manfred
    Hanke).
93. Used _min/_max in various places for bbox computations.
94. src/xfig/plot.sl: Add support for lists in convert_to_array.
95. src/xfig/plot.sl: Allow uninitialized reference in
    get_reftype_qualifier.
96. src/xfig/latex.sl: If the chksum module is present, use it create
    autoeps cache filenames based upon the sha1 checksum of the latex
    code.  This makes the separate epscache.dat file obsolete.
97. Added labelsize qualifier to xfig_new_legend.
98. src/xfig/core.sl: Added jpeg output option.
99. src/xfig/polyline.sl: pict.rotate was not rotating the actual pict
    objec, just its bbox.
100. src/xfig/plot.sl: Allow the depth qualifier to be NULL.
101. Added patches from Manfred: documentation updates, render to a
     specified depth, different dvips methods.
102. tweak the tic code in plot.sl
103. xfig_new_photon: add npts qualifier to specify the number of pts
     per period.
104. Added support for W3C colornames, and a new example showing the
     colors (examples/pict/colornames.sl)
105. Justification qualifiers added to the xfig_new_h/vbox_compound
     functions: c = xfig_new_vbox_compound (a,b;just=-1) will left
     justify the objects.
106. src/xfig/polyline.sl: The rotate method was not rotating surface
     normals.
107. src/xfig/core.sl: autoload readascii (Thomas Dauser).
108. src/xfig/core.sl: Moved xfig_meshgrid from plot.sl, and
     reindented plot.sl
109. src/xfig/plot.sl: Tweaked the code to xfig_multiplot, and
     reformtted its documentation.
110. examples/plot/scilabel.sl was not in the git repository.
111. src/xfig/core.sl: A "fig" qualifier added to the render method:
     If 0, the .fig will be removed, otherwise it will be kept.  The
     default is 0.
112. src/xfig/plot.sl: xfig_plot_new supports ticlabel qualifiers to
     define defaults.
113. Merged Manfred's updates:

       new example showing xfig fill-styles
       added description of 'format' qualifier to xfig_plot.axis
       documentation update reflecting change 112
       Experimental support for for rendering LaTex as tranparent PNGs.
         (See examples/transparent/README)

114. mandlebrot.sl,font-style.sl: minor (cosmetic) tweaks: z^2 -> z*z
     and avoid \ at end of string literal (so that editors such as jed
     do not have to understand the semantics associated with backtick
     strings).
115. src/xfig/latex.sl: If an executable cannot be found on the path,
     enable verbose mode for better error checking.
116. src/xfig/latex.sl: in xfig_new_text set dvi2eps_method to 3 (was
     2) for rotated text (Sebastian Falkner).
117. src/xfig/plot.sl: %.add_object was not working correctly if a log
     qualifier was given and was called before %.plot. To fix this
     %.add_object now initializes the plot. (Sebastian Falkner)
