Implement cross-project Markdown references

Fix fa-download icon

Test for the correct link text in cross-project references.

Display the '@' character for links to commits in other projects.

Display the project path in links to issues in other projects that use
an external issue tracker.

Minor ui improvements

See merge request !1152

Add a note to merge requests and issues when they're mentioned by a
merge request, issue, or commit in another project.

Store both the project and identifier of extracted references.  This
prevents `ReferenceExtractor` from returning objects in the wrong
project for cross-project references.

The cross-project reference feature broke the ReferenceExtractor class;
this fixes it.

Enable linking to commits, merge requests, and issues in other projects
by prepending a namespaced project path to the reference.

Add Pushover service integration

That introduce select field type for services options.

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

Conflicts:
	app/views/projects/edit_tree/show.html.haml

New milestone and label links

Fixes #1364

Fixes #1586

See merge request !1145

Signin after confirmation

Fixes #1471

See merge request !1146

Remove outdated comment on the project test seed

Remove assignment without effect.

Upgrade to Font Awesome v4.2

Add tag push events to project hook api

More information in merge request hook

Merge branch 'factor-commit-msg-textarea' of https://github.com/cirosantilli/gitlabhq into cirosantilli-factor-commit-msg-textarea
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Conflicts:
	app/views/projects/blob/_remove.html.haml

Bump org-mode to 0.9.9

add HSTS Policy warning

add sign-in count

Source repo is now clickable.

Add parenthesis to function def with arguments.

Add move to html-pipeline-gitlab to changelog

Remove test line without effect because no should.

Improve remove file oommit message textarea placeholder.