Gitlab Geo: Authentication

Initial internal API for discovery and authentication for the gitlab-org/gitlab-ee#76

See merge request !112

Add administration section to git-annex doc.



See merge request !132

[ci skip]

CE upstream



See merge request !131

Remove '(EE-only)' from Elasticsearch list item



See merge request !137

[ci skip]

- Rearrange sections
- Limit lines to 80 chars
- Fix typos, grammar, etc.

[ci skip]

[ci skip]

Rails updated to 4.2.5

I hope it'll fix weird spec failing (according to https://github.com/rails/rails/pull/22383)

@dzaporozhets @yorickpeterse 

See merge request !2591

Install unzip in build environment [ci skip]



See merge request !2593

Update gitlab_git & use new method for counting branches

Corresponding gitlab_git merge request detailing some of the rationale behind this: https://gitlab.com/gitlab-org/gitlab_git/merge_requests/62

Fixes #12418 

See merge request !2535

Admin area: doesn't show a note when it's empty

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/12636

See merge request !133

Add note on artifacts browser functionality

Based on the following comment:
https://gitlab.com/gitlab-org/gitlab-ce/issues/12634#note_3359006

See merge request !2586

Based on the following comment:
https://gitlab.com/gitlab-org/gitlab-ce/issues/12634#note_3359006

[ci skip]