Stuff to add to vimage:
Add support for BMP, RLE, PCX, IFF.
Improve speed of Heckbert median cut algorithm.

Have slide file reader accept ~ to mean the user's home directory.

Add command-line gamma correction switch.

Add "control panel" for file selector to change resolution, quantizing
  method, delay time, loop count, etc.
Display ~ rather than user's home directory name in file selector.

Add scrolling for larger-than-screen pics.
Add color correction capabilities (this option is not very useful
  unless we can save).
Add cropping capabilities (ditto previous comment).
