Reasonable pht pass at auth.

Summary: Spent some time going through auth stuff for pht's.

Test Plan: Tested logging in, logging out, reseting password, using Github, creating a new account. I couldn't quite test everything so will double read the diff when I submit it.

Reviewers: epriestley, btrahan

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D4671