Import the database as the `git` user

This ensures that all tables created during the import belong to `git`.
If you import as a different user, such as the `postgres` superuser, you
may encounter issues where the GitLab database user cannot access tables
in gitlabhq_production, _even if_ `git` is the owner of
gitlabhq_production at the time of import.
Cleaner UI for login/signup pages

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Set charset encoding to UTF-8 for snippets

Fixes #2678

Signed-off-by: Jeroen van Baarsen <jeroenvanbaarsen@gmail.com>
Use one word per line in Gitlab::Blacklist
Add 'unsubscribes' to the paths blacklist

GitLab EE has a /unsubscribes/ route.
Always set the origin remote in satellite actions

This prevents issues with satellites containing outdated origin remotes
after administrators move the git repositories directory.
change X-Frame-Options to SAMEORIGIN

needed to allow sidekiq to load on background jobs tab
unify nginx config files
remove prerelease note from 6.0 to 7.2 guide
clarify which configs should be updated
7.3 started
Remove outdated 6.0 to 7.1 update guide