Merge pull request 'feature/enable_gpu_numerical_tests' (#26) from peters/VirtualFluids_dev:feature/enable_gpu_numerical_tests into develop

Merge pull request 'MemoryUtil can determine total physical memory on macOS' (#25) from marcus/VirtualFluids_dev:feature/memoryutil-macos into develop

Merge pull request 'feature/extends_readme' (#10) from peters/VirtualFluids_dev:feature/extends_readme into develop

Merge pull request 'Adds a new constructor to SetKernelBlockVisitor with num processes' (#24) from marcus/VirtualFluids_dev:develop into develop

visit method throws exception if required memory determined from simulation grid exceeds available physical memory

Merge pull request 'CMake Clean Up.' (#22) from peters/VirtualFluids_dev:feature/adapt_to_open_source into develop

Remove VirtualFluidsDefinitions.h header file.
Remove redundant compiler definitions from gpu.cmake.

Few refactorings in cmake. Remove the old openmp flag. Put the intel and gcc libraries in the compiler file.

Make use of the new cmake command: target_link_options, target_compile_options and target_compile_definitions.

Removed unused machine config files.
Removed CAB_COMPILER variable. compiler flag files is now loaded regarding the CMAKE_CXX_COMPILER_ID variable:
	https://cmake.org/cmake/help/latest/variable/CMAKE_LANG_COMPILER_ID.html
Removed the 64 bit support.

Move VirtualFluids header to src.
Add CI file and add files, only existing in the open source version.

Merge pull request 'Update MuParser to version 2.3.2 from 17.06.2020.' (#21) from peters/VirtualFluids_dev:feature/update_muparser into develop

Therefore the muparser cmakeLists.txt was used, but a modified:
 - name is corresponding to the original file: muparser (in lowercases)
 - removed the install
 - adds public include directory : CMAKE_CURRENT_SOURCE_DIR/include.  --> also adapt the include from the dependent fles.
 - adds link to OpemMP

CXX 11 is now required. (CMake throws an error if cpp11 is not available).

Merge pull request 'Little Refactorings in the 3rd cmake part.' (#20) from peters/VirtualFluids_dev:develop into develop

Exclude the cmake .in.h file from the cmake target.

* feature/clean_3rd_cmake_macros:
  Add 3rd library cmake functions.
  Fix gpu cell type.
  Add public include directories.
  CMake: rename the directory variables in a consistent way.
  Remove redundant PointerDefinition file. Make the cmake project more flexible while removing the CMAKE_SOURCE_DIR usage.
  Remove all old unused cmake files.
  Update gitignore file.
  Fix cell type to unsigned int. Adapt basics CMakeLists according to develop.
  Adapt open_source basics to develop.
  Remove unnecessary files in basics.

# Conflicts:
#	CMake/VirtualFluidsMacros.cmake
#	CMakeLists.txt
#	apps/cpu/LidDrivenCavityCPU/CMakeLists.txt
#	apps/gpu/LidDrivenCavity/CMakeLists.txt
#	apps/gpu/LidDrivenCavity/LidDrivenCavity.cpp
#	cpu.cmake
#	gpu.cmake
#	src/basics/CMakeLists.txt
#	src/cpu/VirtualFluidsCore/CMakeLists.txt
#	src/cpu/VirtualFluidsCore/CoProcessors/WriteBoundaryConditionsCoProcessor.cpp
#	src/cpu/VirtualFluidsCore/CoProcessors/WriteBoundaryConditionsCoProcessor.h
#	src/cpu/VirtualFluidsCore/CoProcessors/WriteMacroscopicQuantitiesCoProcessor.cpp
#	src/cpu/VirtualFluidsCore/CoProcessors/WriteMacroscopicQuantitiesCoProcessor.h
#	src/gpu/GksGpu/CMakeLists.txt
#	src/gpu/GksMeshAdapter/CMakeLists.txt
#	src/gpu/GridGenerator/CMakeLists.txt
#	src/gpu/VirtualFluids_GPU/CMakeLists.txt
#	src/gpu/VirtualFluids_GPU/LBM/Simulation.h
#	src/gpu/VirtualFluids_GPU/Output/FileWriter.cpp
#	src/gpu/VirtualFluids_GPU/Parameter/Parameter.h

Merge pull request 'Add public target include directories to the cmake targets. Therefore the IncludeList.cmake files are not necessary anymore.' (#18) from peters/VirtualFluids_dev:feature/add_public_include_path into develop

Merge pull request 'feature/add_public_include_directories' (#17) from peters/VirtualFluids_dev:feature/add_public_include_directories into open_source