Show categorised search queries in the search autocomplete
Fixes#5885
It works in 3 categories, Dashboard, Groups and Project.
## Dashboard context

## Group context

## Project context

## Screencast

See merge request !4499
It will use $.timeago behind the scene and it does the opposite of what $.timeago does.
$.timefor("Thu Jun 05 2016 23:40:39 GMT+0300 (EEST)") will return "3 days remaining".