MP1-4449 : Fix playlist files (.m3u, etc.) in current playlist view, now if playlist file are in folder and we go in current playlist view, the playlist file will be read and item added to current playlist view.
MP1-4449 : Fix duplicate item added to playlist.
Merge remote-tracking branch 'remotes/upstream/MP1-4449-BUG-Read_playlist_files_being_played_to_add_to_current_Playlist_View' into 1.7.0Fork-BDJ

Conflicts:
	mediaportal/WindowPlugins/Common.GUIPlugins/Music/GUIMusicBaseWindow.cs