MP1-4333 : Fix WM_POWERBROADCAST messages to pass to the plugins
MP1-4333 : Rework handling based on code review comment.
Merge remote-tracking branch 'remotes/upstream/MP1-4333-BUG-Not_all_WM_POWERBROADCAST_messages_are_passed_to_plugins' into 1.6.0Fork-BDJ

Conflicts:
	mediaportal/MediaPortal.Application/MediaPortal.cs