Merge branch 'release-3.3.1'

CHANGELOG

CMakeLists.txt

container/Dockerfile

container/Singularity

core/tests/test_setcompoundschemlib.py

doc/conf.py.in

doc/html/_sources/changelog.rst.txt

doc/html/_sources/modelling/algorithms.rst.txt

doc/html/_static/documentation_options.js

doc/html/actions/index.html

doc/html/actions/index_dev.html

doc/html/buildsystem.html

doc/html/changelog.html

doc/html/cmake/index.html

doc/html/container/docker.html

doc/html/container/index.html

doc/html/container/singularity.html

doc/html/contributing.html

doc/html/core/geometry.html

doc/html/core/graph_minimizer.html