Fix various msvc compiler warnings. With msvc the compiler flags are explicit passed to nvcc with -Xcompiler.

Remove some compiler warnings and added some cuda warning suppressions for the GridGenerator, as they are cluttering the build output.

Warning: [-Wbackslash-newline-escape]
https://stackoverflow.com/questions/31673945/clang-backslash-and-newline-separated-by-space-in-single-line-comment

Renmade HOST in GridGenerator to CUDA_HOST because of a name conflict to MPI

Made VF_GPU work with the "new" cmake

implements a fix in the grid generator, that sets invalid STOPPER_UOT_OF_GRID_BOUNDARY nodes to INVALID_OUT_OF_GRID

the grids now store their number of layers, such that different refinements have different number of layers

implements a new flag in the grid that controls wheter the inner region is defined by triangular mesh or primitive

changes the call structure for findInnerNodes() in inital() to allow conglomerates of primitives and triangular meshes

chaged the if statements after changing the return values of Triangle; changed method "calculateQs"; and fixed method "getBoundingBoxOnNodes"