Add ExternalLinkFilter to Markdown pipeline

Forces a `rel="nofollow"` attribute on all external links.

Addresses internal https://dev.gitlab.org/gitlab/gitlabhq/issues/2314#note_46525

See merge request !727

Instead of using a fork, we subclass the filter and only apply the
`task-list` class to list items that actually are task lists.

Closes #1645

See https://github.com/github/task_list/pull/60

Better handle label references that aren't actually references

Fixes #1690

See merge request !705

Cherrypicks for 7.11

See merge request !1826

Fix Atom feeds.

Fixes #1643 and #1644.

See merge request !688

Updated the gitlab_git gem

Work around a Chrome 43 bug preventing note editing

Fixes #1568 - and I mean "fixes"

I have no idea what causes this or why this fixes it and can't dig into it further right now, but the bug seems like a blocker so this needs to be fixed for 7.11.

See merge request !684

Don't send notifications to mentioned users that don't have access to the project in question.

Fixes internal issue https://dev.gitlab.org/gitlab/gitlabhq/issues/2325.

See merge request !664

Fixes #1651

workaround for buggy lexers

It seems that some lexers can be buggy when used together with git blame.
This results in a 500 error when a user tries to open the blame page in some cases.
The workaround is pretty simple. Not only fall back to plaintext when the file content can't be guessed, but also when the lexer fails.

This closes #1521 and #1646

/cc @DouweM @JobV It would be awesome to have this in a patch release for 7.11 or even in the release. But that's probably to late.

See merge request !683

Add explanation about WIP status to MR form.

![Screen_Shot_2015-05-15_at_13.48.49](https://gitlab.com/gitlab-org/gitlab-ce/uploads/b3f70585255a043f07c61570549a90ba/Screen_Shot_2015-05-15_at_13.48.49.png)

![Screen_Shot_2015-05-15_at_13.49.01](https://gitlab.com/gitlab-org/gitlab-ce/uploads/c9992708c8ef5ef4fa2bcc2c3173b8e3/Screen_Shot_2015-05-15_at_13.49.01.png)

See merge request !666

Don't require DB connection in AttrEncrypted.

See merge request !667

Update installation/update guides for 7.11.

See merge request !665

Fix push event.

Fixes issue with !653.

See merge request !663

Fix reference links in dashboard activity and ATOM feeds.

References like `@user` were not linked on the dashboard activity feed and in Atom feeds, because the reference parser depends on `@project` which isn't set in those situations.

This MR passes the project in question to the reference parsers in an option.

cc @rspeicher

See merge request !653

Spin icon next to "Checking for CI status..."

Stationary spinners make me sad.

See merge request !655

Use count badges with number_with_delimiter helper for issue, commit count

See merge request !658

Fix bug with default timezone en RSS gitlab events

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Add order option for projects API

https://dev.gitlab.org/gitlab/gitlab-ci/issues/222

See merge request !656

Refactor SessionsController to use a controller concern

See merge request !659

Fix broken view when viewing history of a file that includes a path that used to be another file

Requires gitlab_git to v7.1.12 to be tagged and released.

Closes #1598

See merge request !651

Add style for <kbd> element in markdown

Fixes #5825