A bunch of patches as commented in rvn's own log

This was my fiddling with your neat little program for my own edification and amusement -- I'm sure you won't want all the changes, but perhaps you'd like some. Revisions 33 and 36 are the significant ones; I made 33 after running into trouble from the () in the original log messages #30 and 31, before I manually quoted them in the rvn.rvn file as it was then.

r: 36 # clearer commit() code
r: 35 # clean up commit()
r: 34 # don't use less, I'll type it myself if I want it
r: 33 # store log messages commented so shell metacharacters don't fuck it up
r: 32 # fiddle with log code
r: 31 # "cosmetically better usage()"
r: 30 # "refactor usage()"
r: 29 # capitalization
r: 28 # more reformatting
r: 27 # a little reformatting