2/2 winex11: add 32-bit pixmap support when XRender is around

[Roderick Colenbrander]

Hi,

This patch adds support for 32-bit pixmaps when XRender is around. The
alpha channel of 32-bit DIBs should not get lost thanks to this patch.
The patch has been tested using various win32 programs and none seemed
to fail. Second it has been tested with some unposted
bitblt/stretchblt tests by Joel Holdsworth and these tests also
passed.

Regards,
Roderick Colenbrander