categories.conf: add app-cdr
Introduce app-cdr/ccd2iso
categories.conf: Add games-action
Introduce games-action/CatacombSDL

This is almost completely useless. I _know_ that. I'm _not_ sure why I'm
doing it anyway.
repository_mask.conf: Mask CatacombSDL[~scm]
categories.conf: Add net-irc
Introduce net-irc/ii
categories.conf: Add net-im
Introduce net-im/venom
repository_mask.conf: Mask venom[~scm]
vifm: bump to 0.7.7 and fixes

- exlibify
- move to github
- add scm version
- notes on test failures, etc.