Help and usage messages Specify that the help option causes the program to exit immediately. Standardize order of options then positional arguments.
Refactored code into multiple 'packages'. One day these may be independently installable. For now it's just an organization method. Rewrote main README and added per-package READMEs. Also: bug fix on whiched and whichvi. They formerly propogated an error if $EDITOR or $VISUAL were set to a non-existant executable. Also improved the inline documentation.
Initial commit of cleaned-up dev branch