Mantis #4483 : don't send duplicate ACTION_NEXT_ITEM or ACTION_PREV_ITEM within 2 seconds when video to music is playing to avoid MP hang. It should solve hang into MyMusic / MyPicture (during slideshow between with resume/pause music)
Extend some video extensions to default list.
Merge remote-tracking branch 'remotes/upstream/BUG-4483_music_to_slide_show_can_hang_MP_wrong_behaviour' into 1.4.0Fork_SEB_New_Master

Conflicts:
	mediaportal/Core/MusicPlayer/BASS/BassAudioEngine.cs
Merge remote-tracking branch 'remotes/upstream/FEAT-4485_Some_video_extensions_missing_from_default_list' into 1.4.0Fork_SEB_New_Master