Bugs in current version:

1)  The high-pass filter option does not work correctly.  It is better to
    use the elliptical filter for high-pass for now.

2)  There is no way to undo editing commands other than restoring the most
    recently saved version from disk.  This is partly due to the lack of
    code on my part (it will be added though) and partly due to lack of
    enough memory to save the original portions.

3) The gravy command will malfunction if the framesize is too small and the
   length factor too large.  This is also being fixed.

4) Not all the dialog windows have a default button for <cr>.  This is a
   toolkit problem, and nothing is currently being done to fix it.

5) In the new data windows: a) The reverse-video boxes will not redraw
   correctly if the window is scrolled in between box drawings. b) The menu
   commands sometimes fail due to the fact that some window managers miss 
   EnterNotify Events, and those events are needed for mixview to determine 
   which data window you are in.
