wined3d: Let WineD3D_ChoosePixelFormat operate on the pixel format database we store at WineD3D startup.

wined3d: Store more information about pixel formats. This is needed for some WineD3D_ChoosePixelFormat restructuring.

This reverts commit 33e561f5.
Fixed the test that fails on all platforms.

The detection algorithm should be good enough for that case now.

Move the writing of include directives into the generated header into 
header.c.

widl: Make the rules for parsing fields in structures, encapsulated unions and non-encapsulated unions more strict.

Move the rules in fields that handle empty union cases into separate 
union rules so that they can't erroneously be accepted for structures or 
other types of unions.