Remove references to tags in Rakefile
Add author
Merge pull request #106 from ADubus/fix-rakefile-tags

Fix task seed in Rakefile
use a single index in elasticsearch for both document types.

WARNING: Must rebuild search index!

Starting with this change, the name of the search index used by the
service has changed.  The new search index must be created before
deploying this version of the application.  There are two ways of doing
this:

* Offline (recommended)
Follow [these instructions](https://github.com/edx/cs_comments_service/wiki/Search-Indexes#offline-procedure) to perform an offline rebuild.

* Online
1. Deploy this code to a host which is not serving HTTP requests, and
run `rake search:rebuild`
2. When the rebuild finishes, deploy the updated code on live servers.
3. run `rake search:catchup[MINUTES]` where minutes is the amount of
time it took to run rebuild in step 1.
4. run `rake search:prune`
Merge pull request #107 from edx/jsa/single-index

use a single index in elasticsearch for both document types.
Refactor search code

This contains several improvements and bug-fixes:

* Take advantage of indexing changes in ead2f5e to reduce the number of
  round trips to execute a search
* Use Tire scan to include all matching threads
* Execute final sort/pagination in Mongo
* Share sorting code
* Eliminate separate presenter for search results (which removes unused
  highlighting functionality)

JIRA: FOR-607
Add spelling correction to text search queries

If a search has no results, then we will get suggestions from
Elasticsearch, re-query with the top suggestion, and return the results
from that query along with the suggestion that was used.