cmake checks for compilerversions

[TakaTuka]

There are some checks of configurations possible to prevent errors between C++14 and nvcc Compiler.

[gentryx]

CMake should check if the C++ compiler supports C++14 (done), CUDA is available (done) and if CUDA supports C++14. If not then we're in trouble and the user needs to decide which feature (C++14 or CUDA) to use.