MP1-4423 : Free left GCHandle (ffdshow).
Merge remote-tracking branch 'origin/MP1-4423-BUG-Memory_leak_in_BASS_Player' into MP1-4423-BUG-Memory_leak_in_BASS_Player
MP1-4428: MP and Configuration Crash after install BassBox Plugin only
MP1-4428: Update bass_vis.dll
MP1-4423: In some cases the GCHandle was freed to early, causing crashes.
MP1-4393 : use/define Full3D constant value.
Merge remote-tracking branch 'remotes/upstream/master' into 1.7.0Fork-BDJ
Merge remote-tracking branch 'remotes/upstream/MP1-4423-BUG-Memory_leak_in_BASS_Player' into 1.7.0Fork-BDJ

Conflicts:
	mediaportal/Core/MusicPlayer/BASS/MixerStream.cs
Merge remote-tracking branch 'remotes/upstream/MP1-4428-BUG_MP_and_Configuration_Crash_after_BassBox_visualisations_are_installed' into 1.7.0Fork-BDJ