[CMake] Including third party libraries

[Hendrik Sattler]

Hi,

I try to include third party libraries when creating the Windows 
package. However, I didn't find an elegant way, yet, to do this.

GetPrerequisites.cmake is fairly hard to use as including and using it 
makes it run at the wrong time. Running it in a CODE install command may 
work but doesn't work nicely with InstallRequiredSystemLibraries.cmake.
Any simple solutions?

HS