Merge branch 'develop' into compile_with_gcc7

.gitignore

CHANGELOG.txt

CMakeLists.txt

actions/CMakeLists.txt

actions/ost-compare-structures

cmake_support/OST.cmake

docker/Dockerfile

docker/README.rst

docker/run_docker_ost

docker/test_docker.py

modules/bindings/pymod/clustalw.py

modules/bindings/tests/test_clustalw.py

modules/conop/doc/aminoacid.rst

modules/conop/pymod/CMakeLists.txt

modules/conop/pymod/wrap_conop.cc

modules/conop/src/CMakeLists.txt

modules/conop/tests/CMakeLists.txt

modules/doc/actions.rst

modules/doc/contributing.rst

modules/gfx/src/vertex_array.cc