Introduce Gitlab::Database.with_connection_pool

See merge request !9192

Move /projects/fork/:id to /projects/:id/fork in V4 API

Closes #14492

See merge request !8940

Fix ActiveRecord connection leaks

Closes #27949 and gitlab-com/infrastructure#1139

See merge request !9109

Add discussion events to contributions calendar

Closes #22645

See merge request !8821

Display loading indicator when filtering ref switcher dropdown

Closes #27966

See merge request !9144

Add omniauth-oauth2-generic strategy

Closes #26744

See merge request !9048

Add GFM support to nested groups

See merge request !9184

Feedback:
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/9192#note_23293693

Fix UX Guide apostrophe use for singular common nouns

See merge request !9190

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Replace static fixture for behaviors/quick_submit_spec.js

See merge request !9086

Replace static fixture for merge_request_tabs_spec.js

See merge request !9172

Make deploy key not show in User's keys list

Closes #27480

See merge request !9024

- Allows configurable Single Sign On with most simple OAuth2 providers
- Adds documentation for the new strategy

Closes #26744

Remove deprecated templates endpoints in V4

Closes #22818

See merge request !8853

Add option to receive email notifications about your own activity

See merge request !8836

Show mentioned/issues being closed from a Merge Requests title

Closes #24333

See merge request !9194

Resolve "GroupsController#activity.json is REALLY slow due to SQL"

Closes #27395

See merge request !9088

Enable Style/RedundantException, Lint/EmptyWhen, and RSpec/ExpectActual cops

See merge request !9151

Respect autocrlf setting when creating/updating file through web UI

Closes gitlab-com/www-gitlab-com#1152

See merge request !9198

Add indices to improve loading of labels page

Closes #25413

See merge request !9121

Signed-off-by: Rémy Coutable <remy@rymai.me>

only print errors and warnings from webpack dev server

See merge request !9118

Fix current build arrow

Closes #27939

See merge request !9154

Show directory hierarchy when listing wiki pages

Closes #23535

See merge request !8133

We don't need to connect when requesting the name of the database
adapter. This in turn should prevent us from requesting/leaking
connections just by asking whether we're using PostgreSQL or MySQL.