Dragging of tracks into channels (GUI part)
Linked together Channel model and Channel Widgets. Clicking the buttons
calls the correct model methods, and the channel updates to show the
current track.
Added paused state to channel, and replaced play/pause with a single
toggle button. Also added images for the buttons.
Persistence layer! Tracks are now loaded from CouchDB (instead of being
hard-coded). It's also a bit more MVC-like, and the tracks model updates
the view when stuff changes.
Merge pull request #31 from MatthewDooler/development

Development