Quick rewrite to tee-less design
Rip out rest of code that supported simulatnous outputs
Get rid of current volume element (fixes #115)
Add debug proxy helper.

Tool sits in front of MPD and Mopidy proxying commands to both. Only the
reference backend's replies are passed to the client. All requests are logged,
but only the response's unified diff is displayed.

Intended use case is quick and simple protocol implementation comparisons.
Add color to console output and fix some things from review.
Add debug-proxy to 0.8 changelog.
Merge pull request #157 from adamcik/feature/debug-proxy
Merge branch 'develop' into feature/simplify-outputs

Conflicts:
	docs/changes.rst
	mopidy/gstreamer.py
Use recommended shebang for Python scripts
Continue ripping out multi output support.
Merge branch 'develop' into feature/simplify-outputs
Add removal of multiple outsputs support to changelog.
Replace OUTPUTS with OUTPUT and switch to simple outputs that return a gst.Bin
Use current_playlist.length instead of len(current_playlist.tracks)
Fix crash in 'playlistinfo' when called with a songpos not matching an CPID (fixes #162)
Make settings.OUTPUT a GStreamer bin description.
Update docs with latest OUTPUT changes and fix issues raised in review of pull request.
Merge branch 'develop' into feature/simplify-outputs

Conflicts:
	docs/changes.rst
Merge branch 'feature/simplify-outputs' into feature/switch-to-gst-mixers

Conflicts:
	mopidy/gstreamer.py
	mopidy/outputs/local.py
Convert to only using GStreamer mixers.