Include wmcodecdsp.h and remove duplicate GUID definitions.

Based on a similar commit of LAV Filters.
Simplify build_ffmpeg.sh now that we use out-of-tree compilation.
Use a bitcheck instead of casting.

The result of a cast from unsigned to signed isn't defined by the specs.

Fixes CID #965944.
Updated Simplified Chinese translation
MainFrm: fast exit play command while opening
MainFrm: don't paint m_pCAP until the rect is set
MainFrm: don't pause the graph in graph thread

Interface repainting may be sluggish after it, instead, enter play or
paused state from main thread after everything is repainted
MainFrm: set icon before constructing the graph
MainFrm: add new MLS_FAILING load state
MainFrm: use strongly-typed enum for load states
Update lcms to 579b3aa.
Update Inno Setup's Traditional Chinese translation.
SubPic: Added XySubPicQueueImpl for a XySubFilter compatibility layer.
SubPic: Add subtitle consumer interface to SubPicAllocatorPresenter.
VideoRenderers: Fixed ambiguous cast to IUknown.
XySubPicQueue: Reuse bitmaps with the same id.
XySubPicQueue: Only create delivery event once, reuse it.
CXySubPicQueueImpl: Unlock pSubPic when aborting.
SubPic: Support textures with an inverse alpha.

Fixes incorrect rendering of subtitles provided by XySubFilter.
No support in MemSubPic for this flag yet.
SubPic: Add XySubPicProvider class and move all subtitle provider communication there.

Now the XySubPicQueue classes can make use of inheritance and only overload certain methods, reducing code duplication.