Import my music & mixer related wmii plugins
Get my wmii music controls working in i3

- Removed wmii references (pygmi, wmiirc)
- Replaced notify with a simple print stub
- Brought in notify_exception & async from pluginmanager
- Added commands.py to dispatch volume and music commands from the
  command line
- Hooked the new command line interface up in i3 config

Eventually I'd like to have the python script directly grab the
applicable keys and remain open in the background - that should
substantially reduce the latency and allow me to cache which music
players are open like I used to do in wmii.
Ignore .*.swp files