tweaks
moved custom keybindings to inputrc

push-public-key has a usage string, which checks argument number.

deleted/commented-out certain deprecated/unused stuff.

move path munging utils to their own file.
WIP: Breaking up bashrc into multiple "modules".
WIP: continuing to break up bash configuration

 - aliases kept together (but not all of them, e.g., some aliases are specific
   to certain modules).

 - basic history configuration

 - note taking (I should collect the entire system into one module, which I can
   then share with others. This will make installation easy: just add a line to
   source the file in your bashrc.)

 - skid: similar to note taking

 - audio, pdf

 - fixed inputrc problems. For some reason I seem to have broke |C-left and
   \C-right for jumping words. Perhaps I had some existing configuration which
   was overwritten?