Merge branch 'qt5_port' into develop

.gitlab-ci.yml

CHANGELOG.txt

CMakeLists.txt

build_configs/darwin_macports.txt

cmake_support/FindPython.cmake

cmake_support/OST.cmake

deployment/macos/pack.py

doc/conf/conf.py

docker/Dockerfile

docker/README.rst

examples/code_fragments/harmony/glwin.py

examples/code_fragments/harmony/harmony

examples/code_fragments/harmony/harmony.py

examples/code_fragments/mm/ethanol_example.py

examples/code_fragments/mm/ethanol_example_using_topology.py

examples/code_fragments/mm/gb_example.py

examples/code_fragments/trj/test_trj.py

examples/code_fragments/ui/board.py

examples/code_fragments/ui/mdi_example.py

examples/code_fragments/ui/menubar_example.py