Delete various dead/nonuseful PHID code
Summary:
Ref T2715.
- Remove the "PHID" application. phid.query provides a reasonable way for developers to get this data without requiring a top-level application.
- Remove some dead/uncalled code.
Test Plan: No more PHID application. Grepped for callsites.
Reviewers: btrahan
Reviewed By: btrahan
CC: aran
Maniphest Tasks: T2715
Differential Revision: https://secure.phabricator.com/D6511