Correctly find last known blob for file deleted in MR.

Fixes #3092.

When building a new MR, `@merge_request.commits.last` would fail because this delegates to `merge_request_diff` which is still `nil` at that point. I fixed that, and changed some of the logic because showing deleted blob contents didn't previously work for the Compare page, and the UI would show the wrong commit sha for "View File @...".

See merge request !1647

Redirect to a default path if HTTP_REFERER is not set

Safari 9.0 does not yet honor the HTML5 `origin-when-cross-origin` mode,
and it's possible load balancers/proxies strip the HTTP_REFERER from
the request header. In these cases, default to some default path.

Closes #3122

Closes https://github.com/gitlabhq/gitlabhq/issues/9731

See merge request !1646

Update 8.0-to-8.1 update guide

- User needs to update gitlab-git-http-server
- User needs to update Nginx configuration

[ci skip]

See merge request !1625

Simplify patch version updates (less steps)

Update CHANGELOG

Safari 9.0 does not yet honor the HTML5 `origin-when-cross-origin` mode,
and it's possible load balancers/proxies strip the HTTP_REFERER from
the request header. In these cases, default to some default path.

Closes #3122

Closes https://github.com/gitlabhq/gitlabhq/issues/9731

Fix duplicate repositories in GitHub import page

By default, all the current user's repositories are accessible via the
/users endpoint. There's no need to traverse all the organization
repositories as well.

See:

* http://www.rubydoc.info/github/pengwynn/octokit/Octokit/Client/Repositories#repositories-instance_method
* https://developer.github.com/v3/repos/#list-your-repositories

Closes #2523

See merge request !1644

Fix regex in redis version check

By default, all the current user's repositories are accessible via the
/users endpoint. There's no need to traverse all the organization
repositories as well.

See:

* http://www.rubydoc.info/github/pengwynn/octokit/Octokit/Client/Repositories#repositories-instance_method
* https://developer.github.com/v3/repos/#list-your-repositories

Closes #2523

Send an email to admin email when a user is reported for spam

Replaces !1547.

Fixes #2839.

See merge request !1634

Fix missing commit status for widget when no CI service is enabled

Fix for #3082 

/cc @dzaporozhets 

See merge request !1621

[ci skip]

Improve performance when filtering on milestone on labels

Also some minor refactoring in the seeding.

See merge request !1587

[ci skip]

Restore notification footer text

See merge request !1640

Remove some padding from code blocks

This creates a weird "leading indent" on the first line of code blocks, at least in Chrome 46, and ends up making the first row not line up nicely with everything else.

![Screen_Shot_2015-10-14_at_2.40.38_PM](https://gitlab.com/pioto/gitlab-ce/uploads/5434eb077c17e56528a94079afe3c732/Screen_Shot_2015-10-14_at_2.40.38_PM.png)


See merge request !1596

Implement new UI for user page. Part 1
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

See merge request !1615

Improve performance of sorting milestone issues

This will fix the problem described in #3066.

See merge request !1609

This cuts down the time it takes to sort issues of a milestone by about
10x. In the previous setup the code would run a SQL query for every
issue that had to be sorted. The new setup instead runs a single SQL
query to update all the given issues at once.

The attached benchmark used to run at around 60 iterations per second,
using the new setup this hovers around 600 iterations per second. Timing
wise a request to update a milestone with 40-something issues would take
about 760 ms, in the new setup this only takes about 130 ms.

Fixes #3066

Add ability to remove the fork relationship from project settings

![Screen_Shot_2015-10-18_at_12.37.24](/uploads/676571642a4c90f7f286280d714599a3/Screen_Shot_2015-10-18_at_12.37.24.png)
![Screen_Shot_2015-10-18_at_12.37.28](/uploads/1a069ecfc4cd3b5438772a9c3f04b6fc/Screen_Shot_2015-10-18_at_12.37.28.png)

Replaces !1579.

Fixes #2578.

See merge request !1636

Close issues mentioned in MR description when MR is merged using
fast-forward merge or when merge commit message is edited.

Fixes gitlab-org/gitlab-ee#48.

See merge request !1639

Allow users to select the Files view as default project view


![Screen_Shot_2015-10-17_at_19.24.01](/uploads/c3194db856f5e5e1b3493302c0a479a5/Screen_Shot_2015-10-17_at_19.24.01.png)

Also shows the readme at the very bottom, like on the regular Files page.


Replaces !1489.

Closes #2655.

See merge request !1632

[ci skip]

Fix bug where a push would only create cross references from the first commit.

Apparently we can't `return` from a `Hash.new` block. Who knew.

See merge request !1638

Fix spelling of Description

[ci skip]