Remove some unused Releeph field methods
Summary: Ref T3718. Remove bulkLoad() and header-view rendering wrappers.
Test Plan: Viewed a request, looked the same. grep'd for stuff.
Reviewers: btrahan
Reviewed By: btrahan
Subscribers: epriestley
Maniphest Tasks: T3718
Differential Revision: https://secure.phabricator.com/D8809