pht() for view and form elements

Summary:
actually just wanted to pht() the Cancel button.

includes pht()ed exceptions.

refrained from pht()-ing phabricator_relative_date() since I wasn't too sure about the effects.

Test Plan: visited all form elements that I remembered - looks reasonable

Reviewers: epriestley, chad, btrahan

Reviewed By: chad

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D5175