Merge branch 'open_source' into feature/merge_clang_tidy

# Conflicts:
#	apps/cpu/LidDrivenCavity/LidDrivenCavity.cpp
#	src/cpu/VirtualFluidsCore/BoundaryConditions/BoundaryConditions.h
#	src/cpu/VirtualFluidsCore/CoProcessors/WriteBoundaryConditionsCoProcessor.cpp
#	src/cpu/VirtualFluidsCore/CoProcessors/WriteMacroscopicQuantitiesCoProcessor.cpp
#	src/cpu/VirtualFluidsCore/Data/D3Q27EsoTwist3DSplittedVector.cpp
#	src/cpu/VirtualFluidsCore/Data/DistributionArray3D.h
#	src/cpu/VirtualFluidsCore/LBM/CumulantK17LBMKernel.h
#	src/cpu/VirtualFluidsCore/LBM/LBMUnitConverter.h
#	src/cpu/VirtualFluidsCore/Parallel/NullCommunicator.h
#	src/cpu/VirtualFluidsCore/Visitors/SetConnectorsBlockVisitor.h
#	src/cpu/VirtualFluidsCore/Visitors/SetKernelBlockVisitor.cpp
#	src/cpu/VirtualFluidsCore/Visitors/SetKernelBlockVisitor.h