Respect Status and Order in Filter Revisions

Summary:
Filter Revisions button currently resets Status and Order fields.
I've rewritten it to GET form because it doesn't perform any action.
It fixed the problem along the way.

Test Plan:
/differential/filter/revisions/
Status: Open.
Filter Revisions.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, epriestley

Differential Revision: https://secure.phabricator.com/D1771