local: Add friendly help if no local library cache found

Fixes #711
js: Fix console setup, allow mocking of the console
js: Log warning if calling convention is not explicitly set
docs: Update authors
mpd: Support playlists in browse

Playlists are containers similar to directories. Treat them equally to
support playlists when browsing.
Merge pull request #748 from jodal/feature/js-calling-convention-warning

Log warning if no Mopidy.js calling convention explicitly selected
Merge pull request #749 from trygveaa/feature/mpd-browse-playlists

mpd: Support playlists in browse
mpd: Minor code style tweak.
audio: Handle all caps ASX tags.

Also add support for simple asx format.
audio: Handle carriage return in playlist detection
stream: Allow for blacklisting of metadata lookups against URI patterns.
Merge pull request #750 from adamcik/fix/gh-687-playlist-handling

Fix/gh 687 playlist handling
docs: Add PR#750 to changelog
mpd: Test playlists in listall(info)
Merge branch 'trygveaa/feature/mpd-browse-playlists' into develop
Merge pull request #752 from adamcik/fix/gh-660-stream-metadata-blacklisting

stream: Allow for blacklisting of metadata lookups against URI patterns.
docs: Add PR#752 to changelog
mpd: Fix typo in browse handling.
mpd: Remove old exception handling.

This is a leftover from the old dispatcher code that was missed in the
refactor. The call() will never raise a LookupError for missing commands.
docs: Add #741 fix