Add a combaseapi.h header for Windows 8 COM functions

git-svn-id: https://mingw-w64.svn.sourceforge.net/svnroot/mingw-w64@5864 4407c894-4637-0410-b4f5-ada5f102cad1
Add CoCreateInstanceFromApp to ole32.def

git-svn-id: https://mingw-w64.svn.sourceforge.net/svnroot/mingw-w64@5865 4407c894-4637-0410-b4f5-ada5f102cad1
Reimplement CoCreateInstance using CoCreateInstanceFromApp

git-svn-id: https://mingw-w64.svn.sourceforge.net/svnroot/mingw-w64@5866 4407c894-4637-0410-b4f5-ada5f102cad1