Disable DXVA2 Extended Format support for the overlay mixer

Overlay mixer responds badly to these flags, resulting in a black screen in some cases.
Update ffmpeg
Link against the debug runtime when building MSVC debug ffmpeg
dxva2: disable vc1/wmv on Intel GPUs

The latest Intel drivers have started to expose the VC-1 decoder GUID, however
the decoder is still broken and crashes or produces a broken image.
Include wmcodecdsp.h and remove any duplicate GUID definitions
Support VC1/WMV3 Image codecs
(CCCP Patch) CCCP LAV Filters' defaults.

Enable the mixer for now, as Lord had problems with
the Windows one. Maybe with NT6 we'll all be able to
disable this without thinking too much about it :V

Also enable the LAV Splitter's tray icon for testing for now.
(CCCP Patch) Enable some additional things in ffmpeg

Also contains extra stuff to make both build scripts work locally
(CCCP Patch) Make LAV Video prefer YV12 to NV12 on XP
[MPC-HC] Tray icon: Add an optional custom callback for "show property page" events.
(CCCP Patch) Enable colorimetry with VSFilter and overlay

VSFilter either ignores or uses (and doesn't pass on) colorimetry
with overlay.