Merge branch 'develop' into confidential-develop

.gitlab-ci.yml

.gitlab/issue_templates/Bug.md

CONTRIBUTING.md

README.md

helper_scripts/cert_check.sh

install/dist/conf/centos52.conf.php

install/dist/conf/centos53.conf.php

install/dist/conf/debian100.conf.php

install/dist/conf/debian110.conf.php

install/dist/conf/debiantesting.conf.php

install/dist/conf/fedora9.conf.php

install/dist/conf/opensuse110.conf.php

install/dist/lib/debian60.lib.php

install/dist/lib/fedora.lib.php

install/dist/lib/gentoo.lib.php

install/dist/lib/opensuse.lib.php

install/dist/tpl/gentoo/amavisd-ispconfig.conf.master

install/install.php

install/lib/install.lib.php

install/lib/installer_base.lib.php