models: Hide empty lists from repr()

(cherry picked from commit 305a76486d59a4fd24f335b16c80854dd0a232df)

Conflicts:
	docs/changelog.rst
models: Fix equality for fields set to the default

Fixes #837

(cherry picked from commit bdd1fb983b3abbbb604686e63647a8aaaa5d97a0)
models: Make all fields default to None or empty collection

(cherry picked from commit abed15b9e409aaa5f50a689012d875b0903313ea)
docs: Update changelog
docs: Don't refer to the tracklist as a playlist
Merge branch 'master' into release/v0.19.x
Merge branch 'master' into release/v0.19.x
mpd: Enable browsing of empty dirs

This was disabled together with a bunch of other changes without any
explanation in commit f24ca36e5a5b72c886d6d8e8df88be79fb094dda. I'm
guessing that this wasn't intentional, and no test covered the case.

(cherry picked from commit 4e508cd01750bcef9e0e9c7b70798eacd276aef8)
mpd: Remove "Comment" tag type from translator output.

Newer versions of the protocol have removed this tag, so we should as well.
This also works around the issue of #881 which was breaking things with
newlines in comment fields.

The readcomments command seems to replace this, but it seems to only care about
specific extra tagtypes, not the general comment tag we normally collect when
scanning things.

(cherry picked from commit 08a8d5c43be271a41af74ce0c7df9d871cf2b532)
[local] fix modified files not being updated

(cherry picked from commit dfd897832a952c4a7da655f504dc0c162433c539)
docs: Update changelog
docs: Update authors
http: Log errors instead of dying for HTTP startup.

(cherry picked from commit 9a2f8a3e4f5ea80ba0e6c497acfc8bee40a04375)

Conflicts:
	docs/changelog.rst
docs: Add :discuss: shortcut for linking to forum threads
path: Support unicode content when creating file
config: Support UTF-8 in default config

Fixes issue reported at https://discuss.mopidy.com/t/428.

Mopidy-HTTP-Kuechenradio includes a non-ASCII UTF-8 character in its
default config. If Mopidy didn't already have a config file, it crashed
when trying to create the initial config file based on the default
config of all available extensions.
ext: Fix unpacking of VersionConflict exception

Fixes #911
playback: Remove skipped track on next in consume mode

Also adds core level tests of consume behavior on next/prev/eot.

Fixes #902
Merge pull request #919 from jodal/fix/902-consume-track-on-next

playback: Remove skipped track on next in consume mode
docs: Update changelog