Improve UI

* Improve group rename warning
* Refactor select css. Make selects same width

See merge request !400

Improve diffs UI

* replace big button with simple toggle for diff comments
* replace diff stats button with link

See merge request !399

Handle nil restricted visibility settings

Return `true` from `non_restricted_level?` when the `restricted_visibility_levels` setting is nil.  This addresses #2154.

cc @sytse

See merge request !1724

Added binstub for guard

Return `true` from `non_restricted_level?` when the
`restricted_visibility_levels` setting is nil.

This reverts commit 7602cef5.

Signed-off-by: Jeroen van Baarsen <jeroenvanbaarsen@gmail.com>

Fix condensed range in MR push comment.

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/1246

In https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/326#note_984907, you see that the compare page doesn't actually have 39 commits because we're using `first_new_commit^`, which is not always the same as `oldrev`. With this MR, we use `oldrev` instead, which will always work.

See merge request !1721

Api: sort merge_request comments

Add default_scope { order(created_at: :asc, id: :asc) } in Note so comments are sorted when fetched through api.

See merge request !256

Add changelog, license and contribution guide links to project sidebar.

If the version is known, the "Version: 7.9.0pre" button links to the changelog, otherwise a "View changelog" button is shown.

![Screen_Shot_2015-03-18_at_14.22.29](https://dev.gitlab.org/gitlab/gitlabhq/uploads/747acc018ec9a188098e0f0bc4e91cc3/Screen_Shot_2015-03-18_at_14.22.29.png)

See merge request !1708

Bump gitlab_git to 7.1.2

For https://dev.gitlab.org/gitlab/gitlabhq/issues/2151

See merge request !1722

List new commits for newly pushed branch in activity view.

When someone pushes commits, I want to see them, regardless if it's a new or existing branch. If it's a new branch, we compare with the default branch (usually master).

![Screen_Shot_2015-03-17_at_15.49.13](https://dev.gitlab.org/gitlab/gitlabhq/uploads/4cb7e0d833bc83a30197db81d4b273bc/Screen_Shot_2015-03-17_at_15.49.13.png)

See merge request !1711

Fix the order of signin and signup on features page.

See merge request !1720

Extend commit calendar to actually show what commits were made on a date

## What does this MR do?
This MR extends the commit calendar so it acutally shows what commits were made on a date and in which project.
It is based on the optimizations @dzaporozhets made for the calendar.

## Are there points in the code the reviewer needs to double check?
The UI and how the links are generated i guess. That feels hacky at the moment :/

## Screenshot:
![commit_calendar_extend_display](https://gitlab.com/uploads/gitlab-org/gitlab-ce/5bf1631660/commit_calendar_extend_display.png)

I assume that i have to refactor this a bit more to make it a cleaner implementation, so please give me feedback on what needs to be changed :)

See merge request !326