* Include creation time
* Include author without avatar
* Move assignee to the right
* Remove action buttons. IMO they are useless and a bit annoying
* Include comments counter by default, gray it out when there are 0
  comments.

Closes #1321

* Squash project users selectbox and users selectbox into one class
* Move from API autocomplete to GitLab internal one
* Smarter filter for project/group/all issues
* Use selectbox with searchbox for assignee/author/milestone/label
* Switch to ajax filter for issue author/assignee

* move votes block to participants
* make smaller font in sidebar

It is same search like we have at issues page. It allows to quickly
filter merge requests based on title or desription. I copy-pasted some
js code from Issues.js. In future search (filtering) logic should be
refactoed into one class for merge requests and issues

* lighter color for comments count
* better UI for issue assigee.milestone block

Use the path helpers for nested project resources, for Rails 4.1.9
compatibility.