Add a setting to choose what artist tag is used for Artist list population. Closes #482

Handling libraries is hard. It's even harder when everybody has their own needs and ways of managing their library.

The removal of this setting has been controversial, but the old situation wasn't perfect either.
The setting now allow you to use the "artist" tag, "albumartist" or both.
There can be potential implications on the album list that follows an artist selection (since I don't propagate this option to AlbumsFragment), but since I'm not really sure how to approach this I'll address it (if needed : "both" is a great option for albums in my opinion) later.
Cache users are not affected by album handling since it works great anyway.
Reindent settings
Make the "refresh database" actionbar button's label more explicit
Refresh MPD database button back in settings

Users got used for this to be in the settings. Discoverability of the button in FSFragment is poor, so stick it in here too.
Fix lousy translation
widgets: Convert to UNIX line endings.
widgets: Remove duplicated code between widgets.
widgets: Fix a few java docbook warnings.
widgets: Remove unused individual widget updating.

Remove it for now, readd if it becomes useful in the future.
Merge pull request #487 from avuton/master

widgets: Fix line endings, remove duplication, unused code paths, docbook
Fix new Artist tag to use setting broken due to missing "break" statement.
add setting
add strings
add PlaylistAlbum
add size() and hasText() to AbstractPlaylistMusic
PlaylistFragment: import
PlaylistFragment: add vars

Conflicts:
	MPDroid/src/com/namelessdev/mpdroid/fragments/PlaylistFragment.java
PlaylistFragment: playlistAlbumWithSongId
PlaylistFragment: onActionItemClicked

Conflicts:
	MPDroid/src/com/namelessdev/mpdroid/fragments/PlaylistFragment.java
PlaylistFragment: update