Add snippet visibilty as parameter to API doc, closes#1562
## Description
Snippet visibility level was added to API but was not to its documentation.
Related to following commit: 928fc94c3d
@axil Can you review?
See merge request !601
Allow primary email to be set to an email that you've already added.
Fixes gitlab-com/support-forum#106.
When the user sets their primary email to an email that they've already added to their account, this patch makes sure that secondary email record is destroyed, and a new email record is created for the old primary email. This is based on the assumption that in this case no email was meant to be deleted, but the user simply wanted to change which of their emails is primary.
See merge request !591
Don't delete gitlab-test-fork folder after every test run
72a7febead added a forked repository cloned to `tmp/tests/gitlab-test-fork` but because it wasn't added to the list of folders not to delete every run, it was being cloned every run and adding extraneous console output.
See merge request !600
Make Reply-To config apply to change e-mail confirmation and other notifications sent through Devise
Notifications sent through Devise were using the default From: address, and due to a broken test line nothing was actually being run.
The only way to customize the Devise Reply-To field is to use a custom mailer. Moved the e-mail configuration out of the initializers to accommodate this.
Closes#1556
See merge request !596
Add a page title to every page.

The `page_title` helper pushes the provided string at the end of the title, but because of the order that layouts are rendered in by ActionView, the result is always this:
```
<title from view> |
<title from as specified in the controller or by its layout> |
<title from layouts/_head>
```
For example: `Merge Requests | GitLab.org / Gitlab Community Edition | GitLab`.
All a developer needs to know is to put a `page_title` call describing the page in question at the start of every template.
To get everything where I wanted it to go without too much duplication, I had to make some changes around layouts, sidebars and controllers.
See merge request !593
More HTML::Pipeline filters
The big part of this MR is a feature that is intended to test the entire Markdown-parsing process from beginning to end. See `spec/support/markdown_feature.rb` and `spec/features/markdown_spec.rb`.
One big thing this MR fixes is not being able to type a `<` or `>` anywhere. It now gets properly escaped.
This MR also adds three more custom HTML::Pipeline filters:
### AutolinkFilter
Similar to the built-in Autolink filter in that it still uses Rinku for standard http and ftp links, but then does some further processing to allow auto-linking of any URI scheme. See internal issue https://dev.gitlab.org/gitlab/gitlabhq/issues/2239
### SanitizationFilter
Created a simple custom SanitizationFilter that sub-classes the default one and adds our custom whitelisting.
### TableOfContentsFilter
Adds the anchor links to each header. This removes some processing from our Redcarpet renderer.
Closes#800, #1015, #1528, #1549
Closes GitHub [8535](https://github.com/gitlabhq/gitlabhq/issues/8535)
See merge request !584
This groups milestones by title for issue views like it has been done for
the milestone dashboard/project overview. Before milestones with the
same title would show up multiple times in the filter dropdown and one could
only filter per project and milestone. Now the milestone filter is based
on the title of the milestone, i.e. all issues marked with the same
milestone title are shown.
While `escape_once` will create this HTML entity, Nokogiri always
translates it back before it gets to IssueReferenceFilter, so there
should be no danger of erroneous issue links.