Add function to update db to v3
Merge branch 'challenge' into dbv3_DateAdded
Read and set date added. TODO: Insert when reading song.
Merge branch 'dbv3_DateAdded' of github.com:flokuep/Vocaluxe into release-0.3

Conflicts:
	Vocaluxe/Base/CDataBase.cs
	Vocaluxe/Base/CSettings.cs
	VocaluxeLib/Menu/SongMenu/CSong.cs