Bring the "featured exploration" flow within the site

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Create a new exploration and publish it.
2. Click on "Nominate for featured status".

What is the expected output? What do you see instead?

A modal pops up and says "please write to this forum". This seems like too much 
hassle and is a bit of a weird flow.

Instead it would be nicer for the nomination to be recorded in the moderator 
queue, and an email to be automatically sent to moderators, when someone clicks 
the button. There should also be a mechanism for the person who clicked the 
button to get a reply from the moderator.

Original issue reported on code.google.com by s...@seanlip.org on 1 Dec 2014 at 5:02