Make MP Compatible to Windows 8.1 Preview.
MP1-4108 : Fix debug filter building (MPIPTV)
MP1-4110 : Merge remote-tracking branch 'remotes/origin/MP1-EXP-Win81-Preview'
MP1-4090 : Fix Thumbnail check without path (It will solve Trakt and third party plugins on '#selectedthumb' in skin.)
Cleanup code and fix leftover temp generated thumb files.
Merge remote-tracking branch 'remotes/origin/master' into MP1-4100_Rework_Refreshrate_for_multi_monitor