Summary: Adds a first-class Query object for querying NamedQueries. xzibit would be proud.
Test Plan: Updated query edit interface to use this query, verified it works correctly.
Reviewers: btrahan, blc
Reviewed By: btrahan
CC: aran
Maniphest Tasks: T2625
Differential Revision: https://secure.phabricator.com/D6051
