Protected branches UI

![Screen_Shot_2016-04-26_at_15.50.10](/uploads/4b905db031aab412bc01616e0be36c1b/Screen_Shot_2016-04-26_at_15.50.10.png)

![Screen_Shot_2016-04-26_at_15.50.00](/uploads/b09229b364ec5361fce375299d39d99c/Screen_Shot_2016-04-26_at_15.50.00.png)

Closes #14027

See merge request !3929