Merge master into develop

CMakeLists.txt

src/CMakeLists.txt

src/DCPSE/Dcpse.hpp

src/DCPSE/MonomialBasis.hpp

src/DCPSE/SupportBuilder.hpp

...erators/Vector/tests/vector_dist_operators_tests_util.hpp

src/Operators/Vector/vector_dist_operators_apply_kernel.hpp

src/PSE/Kernels_test_util.hpp

src/Solvers/petsc_solver.hpp

src/level_set/particle_cp/particle_cp.hpp

src/level_set/particle_cp/pcp_unit_test_helpfunctions.h

src/level_set/particle_cp/pcp_unit_tests.cpp

src/regression/poly_levelset.hpp

src/regression/poly_levelset_test.cpp

src/regression/regression.hpp

src/regression/regression_test.cpp