Summary:
As per discussion, this primes the existing mobile menu / menu button for "phabricator" and "application" menus.
Design here is very rough, I'm just trying to get everything laid in functionally first. It's based on `frame_v3.png` but missing a lot of touches.
Test Plan:
{F26143}
{F26144}
Reviewers: chad
Reviewed By: chad
CC: aran
Maniphest Tasks: T1960
Differential Revision: https://secure.phabricator.com/D4058
