Fix weird formatting in CScreenSong.cs (no code changes)
Fix showing of song menu if not in category
Fix file-not-found exception
Fix for inconsistent song Menu
Multiple refactoring due to ambiguous meanings
Use always the same xml writer settings
Rename PreviewSelected to more meaningful PreviewId
Remove PreviewId pending stuff (don't need that. If you need a fade or something implement it properly with timer, event... But PreviewId should really be the current preview element)
Remove redundant code
Update preview only when necessary
Merge branch 'release-0.3' into develop

Conflicts:
	Vocaluxe/Base/CConfig.cs
	Vocaluxe/Lib/Playlist/CPlaylistFile.cs
	Vocaluxe/Screens/CScreenSong.cs
	VocaluxeLib/CHelper.cs
	VocaluxeLib/Menu/CMenu.cs
	VocaluxeLib/Menu/SongMenu/CSongMenuFramework.cs
	VocaluxeLib/Menu/SongMenu/CSongMenuTileBoard.cs
Bugfix on Init() function of song Menu
Refactoring w/o functional changes
Remove confusing ActSongId
Fix preview start after song end
Merge branch 'release-0.3' into develop

Conflicts:
	VocaluxeLib/Menu/SongMenu/CSongMenuFramework.cs
Workaround missing length even with prescan on gestreamer
Merge branch 'release-0.3' into develop