R1:17ee71d89643

Use Application PHIDs in Maniphest

Summary: Ref T2715. Switch Maniphest to the new stuff.

Test Plan: Used `phid.query`; `phid.lookup` to load objects.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T2715

Differential Revision: https://secure.phabricator.com/D6516