MusicList: Remove final methods from final class.
MPD: Fix typo with list grouping.
Gradle/IDEA: Updates.
Resources: Reformat.
Resources: Disable unused resources.
MPDroidService: Fix intent action punctuation.
JMPDComm: Move Unknown* into MPDroid.

Translations don't belong in a library, this is easily accomplished in the
main program.
MPD: Remove showArtistAlbumCount().
item: Remove subText(), it's unused and needed maintenance.
Music: Remove unused inner comparator class.
SettingsHelper: Move things out of here to more logical places.

SettingsHelper has become a maintenance nightmare. Every time I've tried to
refactor, I've run away crying. Move most of the stuff out to more logical
places, cleans up in the process.
CachedMPD: Clean up warnings, add documentation.
MPD.java: Don't send close command on disconnect.

The way we disconnect, the command and the actual hard disconnection race. It
has to be one or the other, unless we're going to join the close command.
MPDConnection: Remove password method, it's essentially a one liner.
MPDConnection: Simplify a non-retryable command send.
MPDCommand: Make retry field a local variable.
MPDCallable: Don't extend MPDCommand.

This should make things easier to follow.
MPDConnection: Remove refreshAllConnections.

Unfortunately, the concept is racy; all pings will often happen in one socket.
I'm also skeptical of any added benefit.
MPDConnection: Support UTF-8 exclusively.

UTF-8 support has been exclusive since MPD-0.10.
MPDCommand: Add MPD_CMD_PERMISSION.