start, stop, and restart methods for the channel's mpd process
drop this dupe method
just restart, we'll write the config INSIDE the start method
we have multiple mpd processes now. Since they're attached to Channels, we just boot them up via an initializer
kill play.rb from initializers and move things elsewhere

The module-esque things need to go to lib, and the mpd stuff will go
under music.rb when we boot up all the channels
fix the mpd.conf template