ESify feed detail views, prereq to slimming down the homepage

In order to slim down the homepage, I need to speed up the feed detail views. The homepage is currently fat in order to have everything cached by the time the user heads to the feed detail pages. To slim down the homepage, we need to get the feed detail pages less reliant on the homepage view, and give it its own ES view.

- Should I replace the viewset URL rather than having a new URL appending ```/get/```?
Does the elasticsearch-py lib return 404 if one of the filters doesn't find it?