Notifications dropdown on project page now has descriptions

## What does this MR do?

Adds descriptions to the notification settings dropdown on project pages. Also changed the order of them to make more sense.

## What are the relevant issue numbers?

Part of #12758

## Screenshots (if relevant)

![Screen_Shot_2016-05-31_at_09.35.24](/uploads/b30d82701a13ec15f672139e1225acf5/Screen_Shot_2016-05-31_at_09.35.24.png)

See merge request !4374

Implement compact side nav

## What does this MR do?
Implements new compact nav design   
Note- new navbar icons are in a separate MR (https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4268)

## What are the relevant issue numbers?
Closes #18013 

## Screenshots (if relevant)
![Screen_Shot_2016-06-02_at_3.20.37_PM](/uploads/d31bd17ae47743f1a20d7429b4396e84/Screen_Shot_2016-06-02_at_3.20.37_PM.png)   
![Screen_Shot_2016-06-02_at_3.20.43_PM](/uploads/d03a080a57707b6a2161127f3904fcd5/Screen_Shot_2016-06-02_at_3.20.43_PM.png)

cc @dzaporozhets 

See merge request !4447

Ability to prioritize labels

Closes #14189 

See merge request !4009

Use Knapsack to evenly distribute specs

Try to distribute all tests evenly accross all nodes to reduce the testing time of GitLab CE.

This uses high amount of auto-scaled machines.


See merge request !4240

Workhorse to serve raw diffs

Fixes (partially) #13999

Dependent on: gitlab-org/gitlab-workhorse!45

See merge request !4130

# Conflicts:
#	.gitlab-ci.yml