Add winapi-family support, cleanup idl a bit


git-svn-id: svn+ssh://svn.code.sf.net/p/mingw-w64/code/trunk@6262 4407c894-4637-0410-b4f5-ada5f102cad1
Add new interface definition for IAudioEndpointFormatControl.


git-svn-id: svn+ssh://svn.code.sf.net/p/mingw-w64/code/trunk@6263 4407c894-4637-0410-b4f5-ada5f102cad1
Add new audioendpoints interface defintion file to build.


git-svn-id: svn+ssh://svn.code.sf.net/p/mingw-w64/code/trunk@6264 4407c894-4637-0410-b4f5-ada5f102cad1
Add winapi-family check,  remove wrong _WIN32_WINNT >= 0x601 check


git-svn-id: svn+ssh://svn.code.sf.net/p/mingw-w64/code/trunk@6265 4407c894-4637-0410-b4f5-ada5f102cad1