Disable internal WMV/ASF/DVR-MS splitting and WMV decoding by default.

Microsoft filters are generally more stable for those formats.

This commit fixes #3569 #3679 #3680.
Add missing GUID define for WMV splitting in cffd4fc1705172752c1c7d152f41411a9f41f20c.

Modifying the SDK header instead of ours is a bad idea...
Use conversion constructors to work-around confusing AStyle styling.
Use a bitcheck instead of casting (WIP).

Fixes CID #965944.