zeroconf: Improve log messages
http: Simplify Zeroconf publishing
mpd: Simplify Zeroconf publishing
zeroconf: ::ffff:127.* is also loopback addresses
Merge branch 'develop' into feature/http-startup

Conflicts:
	mopidy/http/actor.py
http: Move Mopidy request handlers to helper method
http: Split socket and server creation
http: Make event emitting testable