#390 Adds basic proxy support for http source
flake8 compliant
flake8 compliant
Merge branch 'develop' of https://github.com/AlexandrePTJ/mopidy into feature/gst_proxy
Assign proxy when source need it (not only http)
Merge branch 'feature/gst_proxy' of https://github.com/AlexandrePTJ/mopidy into AlexandrePTJ-feature/gst_proxy

Conflicts:
	docs/changelog.rst
	mopidy/http/actor.py
audio: Cleanup flake and some style issues
Merge branch 'AlexandrePTJ-feature/gst_proxy' into develop