Merge branch '2329-pg-insufficientprivilege-error-when-starting-gitlab-build-failed-15823054' into 'master'

Removing unless clause on postgresql extension enabling

Closes #2329 and #2302

See merge request !1538

Refactor Prometheus config generator

See merge request !1467

Add a link out to our kubernetes helm docs

See merge request !1541

Create a manual trigger to build package from .com repo also

Closes #2330

See merge request !1539

Use a YAML generator instead of a hand-crafted Chef template.
* Avoids invalid YAML syntax.
* Allows exporter recipes to self-register their scrape configs.
* Allows for easier extensions to the existing configs.
* Minor hack to avoid Chef's attribute magic[0].

[0]: https://tickets.opscode.com/browse/CHEF-3953

This reverts merge request !1527

Add script to process Gettext's PO files.

See merge request !1534

Add script to process Gettext's PO files.

See merge request !1534

Fix bug where OmnibusHelper#not_listening? returned true when service was disabled

Closes #2302

See merge request !1527

Copy licenses.csv file from gitlab-rail to generic location

Closes #1904

See merge request !1447

Add gitlab_shell_timeout option, set timeout for fetch/clone operations

See merge request !1482

Fix ldap_sync_worker_cron and geo_bulk_notify_worker_cron add ldap_group_sync_worker

See merge request !1535

Disable slack notification and docs generation for triggered builds

See merge request !1536

Update database.md with new path for postgresql config. Fixes #2310

Closes #2310

See merge request !1533

Update doc to remove unicorn service file if using existing nginx/passenger

See merge request !1231

See: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/10697

Mattermost site url settings

Closes #2286

See merge request !1531