Merge branch 'cmake-refurb' into 'develop'

.gitlab-ci.yml

CMakeLists.txt

CMakeModules/morse_cmake

CMakeModules/utils.cmake

CPackConfig.cmake

CTestConfig.cmake

Contribs/CMakeLists.txt

Doc/CMakeLists.txt

Doc/Doxyfile-mcss

Doc/Doxyfile.in

Examples/CMakeLists.txt

ScalFMMConfig.cmake.in

Tests/CMakeLists.txt

Tests/GroupTree/compareDAGmapping.cpp

Tests/GroupTree/testBlockedAlgorithm.cpp

Tests/GroupTree/testBlockedAlgorithmDyn.cpp

Tests/GroupTree/testBlockedChebyshev.cpp

Tests/GroupTree/testBlockedMpiChebyshev.cpp

Tests/GroupTree/testBlockedMpiUniform.cpp

Tests/GroupTree/testBlockedRotation.cpp