Don' require libflann_cpp-gd in pkg-config file.

Fix CUDA kd tree (broken by the flann::Matrix::stride change)

changed cuda kd tree code and test to work with the semantic change of Matrix::stride (not the cleanest patch, but it works...)

Fix for compiler error on windows

removed __host__ from the GPU result sets, as xerion reported it to break the windows build. And fixed the cuda cmake build, as the -arch sm_13 was there twice, causing a compiler error