merged banshee part from daschuers_trunk
merged with lp:mixxx
merged from lp:mixxx
merged from lp:mixxx
Merge branch 'before_move' into features_banshee
Compileable but not working.

Conflicts:
	mixxx/src/dlgprefplaylist.cpp
Merge commit '25d57b59dff3947212909634864dd82365c9606b' into features_banshee
Merge branch 'master' into features_banshee
Fixed crash of Mixxx when select Banshee
fixed bpm banshee display
added Grouping and AlbumArtist column to Banshee view
make new coloums work
display rating as starts in banshee view
added missing includes
fix of indentation
some code style clean ups
added write protection hint for other libraries, fix library preferences.
Fix banshee playlist import
renamed addToAutoDJQueue() to  addPlaylistToAutoDJQueue()
split addPlaylistToAutoDJQueue
import tracks via bulk transfer from external library