Annotate models

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

See merge request !1799

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

Add caching for ApplicationSetting, Ci::ApplicationSetting.

ApplicationSetting.current was called in every pages, cache it and expires it after it updated.

This changes will avoid a SQL query in every pages (~0.3 - 0.5ms).

```SQL
SELECT  "application_settings".* FROM "application_settings"   ORDER BY "application_settings"."id" DESC LIMIT 1
```

- Offloads uploading to GitLab Workhorse
- Use /authorize request for fast uploading
- Added backup recipes for artifacts
- Support download acceleration using X-Sendfile

- Add page titles to CI settings.
- Fix CI admin navigation.
- Remove duplicated scope.
- Use monospace font for commit sha.
- Add page title and header title to build page.
- Proper authorization for cancel/retry builds.
- Use gitlab pagination theme for builds and group members.
- Don't paginate builds widget on build page.
- Add badges to commit page Changes/Builds tabs.
- Add "Builds" to commit Builds tab page title.
- Add and use Ci::Build#retryable? method.
- Add CI::Build#retried? method.
- Allow all failed commit builds to be retried.
- Proper authorization for cancel/retry all builds.
- Remove unused param.
- Use time_ago_with_tooltip where appropriate.
- Tweak builds index text
- Remove duplication between builds/build and commit_statuses/commit_status.
- Use POST rather than GET for canceling and retrying builds.
- Remove redundant URL helpers.
- Add build ID to build page.
- Link branch name on build page.
- Move commit/:sha/ci to commit/:sha/builds.

Fix CI badge

The previous code relied on having on ref stored in commit, however the ref was moved to the build.

Fixes #3104

See merge request !1690

The previous code relied on having on ref stored in commit, however the ref was moved to the build.