Merge branch 'stable/iron'

.gitattributes

.gitlab-ci.yml

dev/build-release.sh

dev/docker/.gitignore

dev/docker/Dockerfile

dev/docker/Dockerfile.template

dev/docker/Makefile

dev/docker/README.md

dev/docker/add-user.sh

dev/docker/cvc4.template

dev/docker/env.template

dev/docker/install.sh

dev/docker/opam-init-from-ref-config.sh

dev/docker/opam-install-fc-deps-from-ref-config.sh

dev/docker/z3.template

doc/release/deploy.tex

doc/release/validation.tex

doc/userman/user-plugins.tex

doc/userman/user-start.tex

nix/frama-c-public/publish-opam.sh