help with CMake on win32

[Brad King]

Peter Kümmel wrote:
> we need a kdewin32 before the configure process starts, because
> kdewin32 exports many checked functions to kdelibs.
> 
> So we have somehow to get kdewin32 build befor the configure
> processs starts.

If kdewin32 provides certain functions then there is no need to do a 
try-compile to test for them.  We know we are using the library and that 
it provides the functions.

In the case that we are building kdewin32 then the try-compile results 
should just be hard-coded to true for the functions provided.  I think 
this is what ConfigureChecksWin is supposed to do, but it should be 
included BEFORE the checks so that they are not done at all.

-Brad