Remove obsolete/deprecated withTaskIDs() / withTaskPHIDs()

Summary: Ref T603. These were deprecated some time ago in favor of the more standard withIDs() / withPHIDs().

Test Plan: grep, loaded some interfaces.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T603

Differential Revision: https://secure.phabricator.com/D6929