adds BGKPlus Kernel

src/VirtualFluids_GPU/GPU/BGK27.cu

src/VirtualFluids_GPU/GPU/GPU_Interface.h

src/VirtualFluids_GPU/GPU/GPU_Kernels.cuh

src/VirtualFluids_GPU/GPU/LBMKernel.cu

.../Kernel/Advection/Compressible/BGKPlus/BGKPlusCompSP27.cu

...U/Kernel/Advection/Compressible/BGKPlus/BGKPlusCompSP27.h

.../Advection/Compressible/BGKPlus/BGKPlusCompSP27_Device.cu

...Advection/Compressible/BGKPlus/BGKPlusCompSP27_Device.cuh

...GPU/Kernel/Advection/Compressible/BGKPlus/package.include