Summary:
Ref PHI1292. Enable fulltext searchs in paste. Maybe this should only index a snippet instead of the entire content?
Also updates table names in `PhabricatorPasteQuery`.
Test Plan: Created some pastes, indexed them, searched for them.
Reviewers: amckinley
Subscribers: codeblock, Korvin, PHID-OPKG-gm6ozazyms6q6i22gyam
Differential Revision: https://secure.phabricator.com/D20650
