oleaut32: GetRefTypeOfImplType(0) on TKIND_DISPATCH typeinfos should always return an href to IDispatch.

Add tests that show the strange behaviour of IStream_Read returning S_OK 
instead of an error code.

There should be one host apartment per apartment. Existing apartments 
should not be re-used, except in the case of the main apartment.

comctl32: Trying to blend an image without a mask causes problem, especially if the background is white.