Update .travis.yml
JMPDComm: Fix remaining conditional expressions.
Genre: Remove unused field.
Music: Remove dead code.
Make AlbumInfo constructor check for Album Artist
Add rudimentary support for showing/setting rating of current song.

Ratings range from 0 to 10 and are displayed as 0 to 5 stars with
1/2 star resolution.

External changes are not yet noticed.

Layout is... bad.
Update rating display when the server sends a change notification.
Don't explicitly check whether connected.
Log debug message when notified of a sticker change.
Parse sticker command response w/o regex.
MPDConnection: Add isCommandAvailable().

Add the ability to check for command availablility against the current server.
The command list is pulled from the server on initial connection, so, the
cost is minimal.
stickers: Implement a stickers class.

To attempt to avoid bloating the MPD class with more and more stuff, it's time
to begin making classes outside MPD. This is a, more or less, full MPD protocol
stickers implementation as it stands right now.
NotificationHandler: When not running "L" or better, assume dark theme.
BrowseFragment: Check for the listplaylist command prior to running it.

This allows us to avoid an exception parse if a playlist directory isn't setup
on the connected media server.

This will work only on MPD 0.19.2 or later of the standard MPD implementation.
MPDroid: Code style.
Jump to beginning of current song instead of previous if more than 5 sec have been played
Collapsed Albums: add setting
Collapsed Albums: add strings

Conflicts:
	MPDroid/src/main/res/values-de/strings.xml
Collapsed Albums: add PlaylistAlbum
Collapsed Albums: add size() and hasText() to AbstractPlaylistMusic