Closes #13628

* Add Labels tab to Groups
* Add decorator for label so it's aware of Milestones.

With this change we avoid doing N+1 queries when viewing Milestone's
Issues/MRs from a Group context.

Make methods return ActiveRecord Relations instead of Arrays.

In UsersController#calendar_activities, when Date isn't parsable, fallback to Date.today

For some reason, GoogleBot accesses `/u/:username/calendar_activities` without
a `:date` param, but then the view was trying to call `#to_s(:short)` which
doesn't exist on `nil`, leading to the following Sentry report:
https://sentry.gitlap.com/gitlab/gitlabcom/issues/1182/

See merge request !3074

ctrl+enter on mac correctly submits forms

Closes #4177

See merge request !3089

Updated dropdown CSS

This is a start on #3279 by updating the CSS for the dropdown menu. This doesnt include any CSS for the title bar or filter field

![Screen_Shot_2016-03-04_at_12.23.49](/uploads/6f2047ec1b72974334fa56e6895a32be/Screen_Shot_2016-03-04_at_12.23.49.png)

See merge request !3092

[ci skip]

Added tabindex to filter field

Based on however I changed the tabindex of the search field so that it goes search field -> filter field & then back to browser default. I dont think we should override the default tabindex of the page too much.

Closes #3706 

See merge request !3093

Based on however I changed the tabindex of the search field so that it goes search field -> filter field & then back to browser default. I dont think we should override the default tabindex of the page too much
Closes #3706

This is a start on #3279 by updating the CSS for the dropdown menu. This doesnt include any CSS for the title bar or filter field

Invalidate cache for builds badge

This fixes cache issue with badges (we should not cache badge images).

Closes #13982

See merge request !3086

Closes #4177

Closes #13982

Increase the notes polling timeout over time

Originally by @roperzh at https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/2821

Fixes #13300 

See merge request !3071

SSH keys settings

Closes #13860

See merge request !3034

Prior, we were double-checking `@keys.any?`, and unnecessarily assigning
`is_admin` in a view where it wasn't needed.