[CMake] Policies in generate step

[Dominik Bernhardt]

> -----Urspruengliche Nachricht-----
[...]
>
> Note that cmake_minimum_required(VERSION):
>
>   
> http://www.cmake.org/cmake/help/v2.8.12/cmake.html#command:cmake_minimum_required
>
> will unset policies newer than the specified version number.  If you  
> have not set a policy explicitly since the most recent call to that  
> then the policy will not be set when a target is created, and  
> therefore you may get the warning at generate time.
>
Thanks for that hint. cmake_minimum_required indeed caused the problems.

Dominik