Reorganization in preparation for a major overhaul.

I used distutils before because I always prefer core packages to third-party
libraries. However, distutils isn't sufficient and the...well, the whole thing
sickens me, actually. Packaging in Python is not Pythonic.
Rewrote almost everything.

I need to port the important function, the one that actually manipulates tmux.
This is a pretty good method of handling the configuration, though some things
are still bothering me.