Necessary tasks:
- wmanager.1
  - add a FILES section to the manual pages
  - describe the .wmanagerrc file format
- wmanager-loop.1
- wmanagerrc-update.1
  - add a FILES section to the manual pages
- wmanager-loop
  - add some more commonly-used X terminal emulators
- wmanagerrc-update
  - some kind of error checking
  - *append* to .wmanagerrc.tmp? why not use a temporary file?
  - lockf or something...
