as is done in the Windows headers.
Add #define COBJMACROS where needed in Wine.
Fixes the compilation of the oleaut32/tests/olefont.c and
urlmon/tests/url.c conformance tests with the Windows headers.
- ConvertINetMultiByteToUnicode/ConvertINetUnicodeToMultiByte should
return required target length if the target buffer is NULL
- add the tests for all the above
- fix IMultiLanguage2 vtable (it was missing ConvertStringFromUnicodeEx)
Alexandre Julliard