Further work for Reformat:

These should be done before final release:

- Find out why GIF color tables (all color tables, actually, but GIF in
  particular) don't seem to get converted properly.   (Medium)

- Add more of the types in the PBM library to Reformat.  (Short)

- Update the documentation to reflect the new types.  (Short)

- Build and test on more platforms.  (Medium)



These are optional (and some are of debatable utility):

- Write more specialized conversion routines for those file types most often
  used.  (Long) 

- Improve the user interface to allow specification of multiple conversions.
  (Medium)

- Write a PBM->HDF conversion routine.  This would speed up the conversion of
  file types supported by the PBM library.  (Medium)
 
