THINGS TODO
-----------
* Add an option for user to select between strcmp/strcasecmp/colcomp
  in filename_compare.
  (add tests for each of the options.)

* Make "unload" be more sensible, as to what is the opposite behavior
  of "use", "unuse", "load", & "unload" in unloading a module.

* Use the "module avail" cache even for the module load/unload lookups

* Add --remove (opposite of --create) to remove cache files

* Add "exists" switch to exit with 0 or 1 if the given modulefile
  exists or not.

* Add "exec" switch to execute the given "embedded" Tcl routines
  in modulefiles.

* Add RPM distribution creation to Makefile.

* fix order that and scope of .modulerc files are read in.

* fix the module-alias command.
