Implements upcoming filter in milstones

![Imgur](http://i.imgur.com/Oc2LZrF.png)

@DouweM @JobV I think this is what you wanted :) Lemme know if it there is something that need changing
Had alot of fun doing it!

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/14102

See merge request !3148