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

# Conflicts:
#	src/GridGenerator/grid/BoundaryConditions/Side.cpp
#	src/GridGenerator/grid/GridBuilder/LevelGridBuilder.cpp
#	src/GridGenerator/grid/GridBuilder/MultipleGridBuilder.cpp
#	src/VirtualFluids_GPU/LBM/Simulation.cpp
#	src/VirtualFluids_GPU/Output/FileWriter.cpp
#	targets/apps/HULC/main.cpp

# Conflicts:
#	src/GridGenerator/grid/GridBuilder/MultipleGridBuilder.cpp
#	targets/apps/HULC/main.cpp

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

fixed round of error bugs in Triangle by using method "greaterEqual"; and changed the return values -> change the related Test methods

Includes three checks, whether nodes exist, to allow STLs to be bigger than the grid, IMPORTANT: this only works with