Change before(:all) -> let! to avoid leaking data across tests

Closes https://github.com/gitlabhq/gitlabhq/issues/9495

See merge request !1061

Closes https://github.com/gitlabhq/gitlabhq/issues/9495

Upgrade gitlab_git to version 7.2.6 to fix 500 Error when creating network graphs

See merge request !1060

Closes #745

Added a timestamp to the wikis page just below the title

Now it looks like this:

![image](https://gitlab.com/gitlab-org/gitlab-ce/uploads/813f85496db915cf14ee223c8b15478f/image.png)



See merge request !1055

Return comments in created order in merge request API

Closes #1832

See merge request !985

Fix commit data retrieval when branch name has single quotes

Quotes in ref names need to be escaped properly in JavaScript.

Closes #1724

See merge request !1046

Render Note field hints consistently for "new" and "edit" forms

- The "Edit" form didn't have Markdown hints.
- The "New" form had a paperclip icon for attachments, the "edit" form
  didn't.

Closes #2010

Closes internal https://dev.gitlab.org/gitlab/gitlabhq/issues/2525

See merge request !1049

Add rake task 'gitlab:update_commit_count'

Starting with migration `20150717130904` commit count is stored in the
database. For existing projects it defaults to `0` and is updated to the
correct value when commits are pushed.

The newly introduced rake task updates the commit count for all projects
which have not been updated yet.

![gitlab-rake-update-commit-count](https://gitlab.com/gitlab-org/gitlab-ce/uploads/4785009e0f3fc4c3199fe65dfb8e60e0/gitlab-rake-update-commit-count.png)

Refs !986, !989, #2040, #2089.

See merge request !1040

Create project services on Project creation

Closes internal https://dev.gitlab.org/gitlab/gitlab-ee/issues/306#note_53354

See merge request !1045

- The "Edit" form didn't have Markdown hints.
- The "New" form had a paperclip icon for attachments, the "edit" form
  didn't.

Closes #2010

Closes internal https://dev.gitlab.org/gitlab/gitlabhq/issues/2525

Fix live notes refresh in relative URL deployments

### What does this MR do?

This MR fixes URLs used for refreshing notes--the relative_url prefix was appended twice

### Why was this MR needed?

In case of `relative_url` installation, opening a page which does refresh notes (i.e. merge request), the page generates lots of 404 errors in the browser console. It turns out that the relative_url is prepended to the link twice.

Supersedes !233

See merge request !1048

Closes #1724

Fix the "Reload with full diff" URL button

On the first load, the merge request tabs would be requested in JSON format to render
the HTML. This would cause the "Reload with full diff" button to create a link to `diff.json`. Instead, generate the path in HTML mode.

Closes #2041

See merge request !1019

Dynamically check `:admin_*` ability in two more spots.

Closes #2092 

Depends on !1037 

See merge request !1042

Fix error 500 when no HEAD is available

Steps to reproduce:

1. Create a project with a README
2. In the actual remote, type: `git symbolic-ref HEAD refs/heads/nowhere`
3. Check that HEAD is gone via `git ls-remote .`
4. Go to the projects page and see the Error 500

Error:

```
NoMethodError - undefined method `sha' for nil:NilClass:
  app/helpers/projects_helper.rb:281:in `readme_cache_key'
  app/views/projects/_readme.html.haml:10:in `_app_views_projects__readme_html_haml___2036282917939462960_70154565285700'
  actionview (4.1.11) lib/action_view/template.rb:145:in `block in render'
  activesupport (4.1.11) lib/active_support/notifications.rb:159:in `block in instrument'
  activesupport (4.1.11) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
  activesupport (4.1.11) lib/active_support/notifications.rb:159:in `instrument'
  actionview (4.1.11) lib/action_view/template.rb:339:in `instrument'
  actionview (4.1.11) lib/action_view/template.rb:143:in `render'
  rack-mini-profiler (0.9.0) lib/mini_profiler/profiling_methods.rb:108:in `block in profile_method'
  actionview (4.1.11) lib/action_view/renderer/partial_renderer.rb:306:in `render_partial'
  actionview (4.1.11) lib/action_view/renderer/partial_renderer.rb:279:in `block in render'
  actionview (4.1.11) lib/action_view/renderer/abstract_renderer.rb:38:in `block in instrument'
  activesupport (4.1.11) lib/active_support/notifications.rb:159:in `block in instrument'
  activesupport (4.1.11) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
  activesupport (4.1.11) lib/active_support/notifications.rb:159:in `instrument'
  actionview (4.1.11) lib/action_view/renderer/abstract_renderer.rb:38:in `instrument'
  actionview (4.1.11) lib/action_view/renderer/partial_renderer.rb:278:in `render'
  actionview (4.1.11) lib/action_view/renderer/renderer.rb:47:in `render_partial'
  actionview (4.1.11) lib/action_view/helpers/rendering_helper.rb:35:in `render'
  haml (4.0.5) lib/haml/helpers/action_view_mods.rb:10:in `block in render_with_haml'
  haml (4.0.5) lib/haml/helpers.rb:89:in `non_haml'
  haml (4.0.5) lib/haml/helpers/action_view_mods.rb:10:in `render_with_haml'
  app/views/projects/show.html.haml:47:in `_app_views_projects_show_html_haml__1458303859692972698_70154948164180'
  actionview (4.1.11) lib/action_view/template.rb:145:in `block in render'
  activesupport (4.1.11) lib/active_support/notifications.rb:159:in `block in instrument'
```

Closes https://github.com/gitlabhq/gitlabhq/issues/9484, but there may be some other issue there.

See merge request !1041

Add admin_merge_request ability to Developer level and up

This was necessary because this permission is checked dynamically by
`app/views/shared/issuable/_context` when on a Merge Request.

Closes #2058

See merge request !1037

Closes #2092

Closes #2092

This was necessary because this permission is checked dynamically by
`app/views/shared/issuable/_context` when on a Merge Request.

Closes #2058

Steps to reproduce:
1. Create a project with a README
2. In the actual remote, type: `git symbolic-ref HEAD refs/heads/nowhere`
3. Check that HEAD is gone via `git ls-remote .`
4. Go to the projects page and see the Error 500

Closes https://github.com/gitlabhq/gitlabhq/issues/9484

Starting with migration `20150717130904` commit count is stored in the
database. For existing projects it defaults to `0` and is updated to the
correct value when commits are pushed.

The newly introduced rake task updates the commit count for all projects
which have not been updated yet.

Refs !986, !989, #2040.

Allow custom label to be set for authentication providers.

Addresses internal issue https://dev.gitlab.org/gitlab/gitlabhq/issues/2341

Beside the above, I've:
- Refactored `OauthHelper` to have clearer method names and behaviour
- Moved some of `OauthHelper` behaviour to `Gitlab::OAuth::Provider`
- Renamed `OauthHelper` to `AuthHelper` since LDAP, SAML, Kerberos aren't OAuth
- Updated the icons for GitHub and GitLab

In the examples below, "OurAuth" is a SAML provider with a custom label.

![Screen_Shot_2015-07-02_at_16.29.52](https://gitlab.com/gitlab-org/gitlab-ce/uploads/7d425bde69dc34e1667ebd5375d0266d/Screen_Shot_2015-07-02_at_16.29.52.png)

![Screen_Shot_2015-07-02_at_16.31.40](https://gitlab.com/gitlab-org/gitlab-ce/uploads/cbb273321ecdf4cab3d3ef0dc35553e7/Screen_Shot_2015-07-02_at_16.31.40.png)

![Screen_Shot_2015-07-02_at_16.32.39](https://gitlab.com/gitlab-org/gitlab-ce/uploads/d8dd6e1d0dc45a788e869cdcdc99e178/Screen_Shot_2015-07-02_at_16.32.39.png)

![Screen_Shot_2015-07-02_at_16.33.18](https://gitlab.com/gitlab-org/gitlab-ce/uploads/7dbfe8b0ae229c32a08d6c7442976d83/Screen_Shot_2015-07-02_at_16.33.18.png)


See merge request !927

Fix and style the "Changes suppressed" link.

At some point the "Changes suppressed. Click to show" link stopped behaving as expected, so this fixes it.

I also thought it looked bad:

![Screen_Shot_2015-07-23_at_4.06.49_PM](https://gitlab.com/gitlab-org/gitlab-ce/uploads/0a1552e4edb659f065bd202b93bc61ef/Screen_Shot_2015-07-23_at_4.06.49_PM.png)

So I gave it some room to breathe:

![Screen_Shot_2015-07-23_at_4.00.25_PM](https://gitlab.com/gitlab-org/gitlab-ce/uploads/abc0704e597ed010cade81782ac9099e/Screen_Shot_2015-07-23_at_4.00.25_PM.png)


See merge request !1038

Make username parameter for Users#show case-insensitive

Closes #2012

See merge request !996

On the first load, the merge request tabs would be requested in JSON format to render
the HTML. This would cause the "Reload with full diff" button to create a link to diff.json.

Closes #2041