Merge pull request #496 from avuton/master

NowPlaying*Fragment: Revert the changes to NowPlaying* to fix NPE bug.
Merge pull request #512 from avuton/next

Streaming and Notification Service.
Fix play queue sliding pager setting wrong window title. Refs #509
Pressing back from any other mode than Mode.LIBRARY brings you back to the library instead of closing the app. Fixes #514
Update korean translation
We now acquire a wake lock when streaming. Even if mediaplayer maybe takes one itself, it's great to have our own. Finally fixes #216
Hide "Save" and "Clear" from the now playing menu if not on the play queue
JMPDComm: If title is null, use filename.