Sidebar overlaps content when screen is below 1200px.

When screen is below 1200px, the sidebar overlaps.
When screen is above 1200px, the sidebar pushes content out.
z-index change to make sure hamburger stays on top.
Fixes #12717 
![screensize](/uploads/9a21fa06d583a49d6ebbf1ada34c6792/screensize.gif)

![screensize-small](/uploads/7c25f46e962248a40840562a01c83f8f/screensize-small.gif)

Also sorry I couldn't get the collapse button in the screen cap. It's there. 


See merge request !2620

Shrink on diff view

* Shrinks when navigating to diff view.
* Shrinks when refreshing on diff view.
* Expandable at anytime.

![diff](/uploads/ec3ff1e7be7571a3af251e9ec9f704c1/diff.gif)


See merge request !2735

Fixed ~git beeing displayed as link to issues tagged with git in architecture.md

The architecture documentation explains `~git` from the picture below which is replaced by a [link to issues tagged with `git`](https://gitlab.com/gitlab-org/gitlab-ce/issues?label_name=git). I believe that this was unintended and should be fixed by using backticks.

![Screenshot_from_2016-02-13_21-36-30](/uploads/5ea1a60e8b230952874e58eab0abe1ac/Screenshot_from_2016-02-13_21-36-30.png)

See merge request !2814

Update commit status permissions [ci skip]

cc @axil 


See merge request !2942

update ci configuration to send slack notifications on failure

Updates CI config file and adds a task to send notifications when a build fails on master or on any tag.

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/12805

See merge request !2681

Add "issue" to Close/Reopen buttons for clarity

_Originally opened by @andywgrant at !2884_

---

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/13549

See merge request !2929

Improve the formatting for the user page bio

Resolves #13406.

Problems, per the Issue above:
- The bio has an extra period appended by the HAML view.
- The bio isn't given its own line, not differentiated from username and account creation date.
- The bio is allowed to span almost the full width of the container, would probably look better if it were only allowed a max width of something like 750px.

This commit:
- Separates the User page bio from the username and account creation
date.
- Separates the pseudo-selector adding a Middle Dot out from the
`profile-link-holder` class and into a `middle-dot-divider` class.

Before:
![Screen_Shot_2016-02-15_at_3.55.28_PM](/uploads/fbe410c3f436740121c5f4686e0f44d0/Screen_Shot_2016-02-15_at_3.55.28_PM.png)

With this Merge Request:
![Screen_Shot_2016-02-15_at_3.55.25_PM](/uploads/b4b16376a395608f57d8f76ab47e241f/Screen_Shot_2016-02-15_at_3.55.25_PM.png)

See merge request !2827

Changed padding & background color for highlighted notes

Closes #12453

![Screen_Shot_2016-02-23_at_11.18.59](/uploads/19150d884fd1175fe0df5f6daee64206/Screen_Shot_2016-02-23_at_11.18.59.png)

See merge request !2937

Correctly aligned buttons vertical in gray-content-block

Closes #12790 

![Screen_Shot_2016-02-23_at_15.09.19](/uploads/e5c6d97d8c1712273c87a0d592430390/Screen_Shot_2016-02-23_at_15.09.19.png)

See merge request !2941

Treats activity tabs as single select

Fixes #8092

![activity-tabs](/uploads/1fb4d9233492252cfd93c74579e97514/activity-tabs.gif)

See merge request !2940

Fix look of tooltip for Revert button.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/13602

See merge request !2900

Fix group projects styles

Makes new project button visible when no projects are available.
Fixes #13193 

# BEFORE
![Screen_Shot_2016-02-04_at_1.08.27_PM](/uploads/36be9d5892506e7d1abcf4eb2a622e12/Screen_Shot_2016-02-04_at_1.08.27_PM.png)

# AFTER (w/projects)
![Screen_Shot_2016-02-04_at_1.07.48_PM](/uploads/fa257a1965017ff1274572dc66fccf90/Screen_Shot_2016-02-04_at_1.07.48_PM.png)

# AFTER (no projects)
![Screen_Shot_2016-02-04_at_1.07.28_PM](/uploads/326f6fdac24b56e8408efd0d11dc2805/Screen_Shot_2016-02-04_at_1.07.28_PM.png)

cc @creamzy @skyruler 

See merge request !2714

Fixes #8092

Revert "Remove newrelic gem. Closes #12860"

This reverts commit 53176717.

Conflicts:
	Gemfile.lock

See merge request !2943

Load award emoji picker with ajax request

Fixes #13301.

See merge request !2888

- Separates the User page bio from the username and account creation
date.
- Separates the pseudo-selector adding a Middle Dot out from the
`profile-link-holder` class and into a `middle-dot-divider` class.

Resolves #13406.

See merge request !2827.

Makes new project button visible when no projects are available.
Fixes #13193

Update sentry-raven to 0.15.6

Fixes a few bugs, most notably (for our purposes): https://github.com/getsentry/raven-ruby/pull/450

See merge request !2947

Adds "e" shortcut to issuable pages which redirects to the Edit page

Closes #13510

See merge request !2945

Show Crowd login even when sign-in is disabled

Fixes #13176.

See merge request !2749

Does not raise an error when Todo  is already marked as done

Closes #13681 

See merge request !2926