Refactor sidebar JS logic

Move asana_service_spec to its correct location

properly paginate project events in API

Remove the email patches link for merge commits

Rugged's `to_mbox` method doesn't work for merge commits, so don't display the option to download them as email patches.  This is part of the fix for #1878, and gitlab/gitlab_git!27 allows a plain diff to be generated for a merge commit.  Together these changes should prevent the 500 errors described in the issue.

cc @sytse

See merge request !1737

We've moved external trackers to service, remove from gitlab.yml.

Fixes #1937

See merge request !1743

update acts-as-taggable-on

Change merging notification to sound more natural

Improve UI for issues filters

![filters-ui](https://gitlab.com/gitlab-org/gitlab-ce/uploads/31109bb069a5f42a9b83c2fb44af288b/filters-ui.png)

See merge request !472

Prevent holding Control-Enter or Command-Enter from posting comment multiple times.

See private issue https://dev.gitlab.org/gitlab/gitlabhq/issues/2184

See merge request !467

Fix typo 'projecti' to 'project' in ssh doc [ci skip]

There was a typo in the SSH doc: projecti was written instead of project.

See merge request !461

Big refactoring of issues filters

* No magic numbers for issues filtering
* Squash project users selectbox and users selectbox into one class
* Move from API autocomplete to GitLab internal one
* Smarter filter for project/group/all issues
* Use selectbox with searchbox for assignee/author/milestone/label
* Switch to ajax filter for issue author/assignee

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/1035

See merge request !466

* Squash project users selectbox and users selectbox into one class
* Move from API autocomplete to GitLab internal one
* Smarter filter for project/group/all issues
* Use selectbox with searchbox for assignee/author/milestone/label
* Switch to ajax filter for issue author/assignee

Separate Dockerfile for Data and Application

This is based on #1158

Instead of creating data container from same docker image, we create separate docker image for data container to avoid keeping original docker image after upgrading to new version. (That results in 1GB space that cannot be freed)

See merge request !409

Set Application controller default URL options to ensure all url_for calls are consistent

### What does this MR do?

This MR sets the app controller's `default_url_options` so that all `url_for` calls are consistent.

### Are there points in the code the reviewer needs to double check?

Setting these options may simplify `url_for` calls that load the GitLab options already. I did not want to touch existing code yet. I'm also not sure if there are other options that need to be included.

### Why was this MR needed?

If you run GitLab behind a reverse proxy or in a Docker container, you don't want a user to be seeing the local IP and port on which GitLab is running (e.g. 192.168.1.1:8080). Right now there are places where this internal data is leaked (e.g. see the URL in Profile Settings -> Account -> Username; this uses `user_url`).

### What are the relevant issue numbers / [Feature requests](http://feedback.gitlab.com/)?

#1249

See merge request !453

Fix EmailsOnPush.

See private issue https://dev.gitlab.org/gitlab/gitlabhq/issues/2185.

See merge request !459

Add archived status to Admin > Project page

Renamed Buildbox to Buildkite.

Change directory when removing old backups

Fixes errors when deleting old backups in the `gitlab:backup:create` rake task.  See #2177.

See merge request !1740

Capitalize js class name

See merge request !457