Adding stories to search index.
Changing param names.
Merge branch 'master' into search

* master:
  Fixing two bugs: dont clear mapping/index when re-indexing at offset. Pull on pip upgrades.
Rewriting search to use Elasticsearch across feeds. Much faster, just needs indexing.
Removing stories from search index on delete.
Migration for search indexed feeds.
Default null for new search indexed field for backwards compatibility.
Searching read feeds as well.
Fix crash on async story loading.
Indexing stories on indexes feeds during feed fetch.
Merge branch 'master' into search

* master:
  Fixing sideoptions container's height and width.
Adding task to index user's subscriptions and alert them to progress.
Updating search indexing progress in real-time.
Adding migration for creating search mapping.
Retrying search on search indexing completion. Hiding story content preview when too short.
Lightening feedback colors.
Showing correct unread status in river/unread during search.
Fixing bug with not correctly blurring search.
Preserving order on searches. Also using elasticsearch's paging.
Fixing bug in paging queries.