Use strategy for collision

src/gpu/VirtualFluids_GPU/Calculation/CollisionStrategy.h

...gpu/VirtualFluids_GPU/Calculation/CollisisionStrategy.cpp

src/gpu/VirtualFluids_GPU/Calculation/UpdateGrid27.cpp

src/gpu/VirtualFluids_GPU/Calculation/UpdateGrid27.h

...rtualFluids_GPU/DataStructureInitializer/GridProvider.cpp

src/gpu/VirtualFluids_GPU/GPU/CudaMemoryManager.cpp

src/gpu/VirtualFluids_GPU/Parameter/Parameter.h