CHANGES from V2.1
Added a -n flag to set the number of colours. This changes the same
parameter as -B but you request total number of colours.

CHANGES from V1.4
The fractal generation code has been reworked. There algorithm has been
extended significantly and should be able to generate much better
looking surfaces. There may be a performance hit for some options though.

CHANGES from V1.3
1) There is now a flag to control the horizontal light angle.
2) negative values of the scroll parameter make the image scroll in the
   opposite direction.
3) water reflections have been implemented.

CHANGES from V1.2
1) program now sleeps after a scroll rather than once per column.
2) added a -B flag to control the number of colours needed.
3) added a -q flag that clears the root window when the program exits.
4) fixed memory leak when in `map' mode.

CHANGES from V1.1
Several changes including:
1) There is now a secondary (vertical) light source to add some detail to 
the shadows.
2) There is a -Z flag to reduce the CPU load, once the initial screen has
been generated the program will call sleep once for each column of
pixels.
3) Xmountains creates a pixmap containing the current state of the image.
This is now installed as the background pixmap of the window. This means
that root-window images will remain in place if the program is stopped.
The -E flag disables this feature and explicitly traps expose events
instead. There may be some delay in repainting the window if both the -E
and -Z flags are used at the same time.
