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.
Update markdown reference to external issues

1. Issue may be not only in jira.
2. Rewrite method for support different external issue trackers
Delete mailer queue because we don't use sidekiq_mailer gem and now the mailer queue doesn't exist any more.
change bash to sh
fix bash-ism
Fix missing links and incorrect display of issue numbers for notes, comments, and merge requests
Moved padding from li to a in dashboard groups / projects listing
Removed redundant spans
Remove duplicated setupNoteForm method
Add dealing with newlines for editor to 5.1-to-6.0

backport of https://github.com/gitlabhq/gitlabhq/commit/2d681c0d1ed14bf23c041aa04fa3e77caceda9a1
Update gemnasium-gitlab-service
Update org-ruby
Fix Md style for API.
Fix Md style for projects API doc.
Add labels api authorization. Update permission doc

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Consistency: Capitalize hex values of sugested colors
Use new git max_size in the settings initializer
Merge branch 'git_max_size' into 'master'

Use new git max_size in the settings initializer

This allows us to avoid repeating default max_size setting in the omnibus-gitlab repository.

See merge request !1021
Merge branch 'label-permissions' into 'master'

Label permissions

* Update label permission docs
* Add authorisation to labels via API

See merge request !1020
Fix grammar and spelling