Initial commit of custom UI Mode framework (1 of 2)

Summary:
Round one, we'll bring in force navigation bar. This lays the
core framework for a variety UI mode options including tablet
mode and other navigation possibilities. I'm just getting warmed
up ;D

Change-Id: I3729a65ce353b935341a5c09544d1a6687782871

Test Plan: solid on capkey devices, give it a go!

Reviewers: synergy

Reviewed By: synergy

Differential Revision: http://review.codefirex.com/D436