KDEWIN32 Must be found

[Bill Hoffman]

We need to add something like this to FindKDE4.cmake:

  FIND_PACKAGE(KDEWIN32 REQUIRED)
   IF(NOT KDEWIN32_FOUND)
     MESSAGE(FATAL_ERROR "KDEWIN32 must be found, or try compile results will be incorrect, make sure kdewin32 is built and installed.")
   ENDIF(NOT KDEWIN32_FOUND)
     

The problem is that if you do not find KDEWIN32, all the try compile results will fail.
With this extra check, CMake will stop processing immediately, and not get any bad
answers for the try compile results.   Once you get the wrong answers, you have to delete
the CMakeCache.txt file.  If we do this, then you can specify KDEWIN32 with the cmake GUI,
and continue to configure.

-Bill