Mobile Top Bar, Sub Menu & Scrolling

Summary:
* removes extra title bar
* improves responsive styles
* hides site title on small screens

* Fixes T335
* Fixes T333

* adjusts logo margin
	* Fixes T334

When the scroll bar is active it produces a small UI shift for now `overflow: scroll` fixes the scroll bar jankiness

https://dl.dropboxusercontent.com/u/1852677/scroll%20bar%20jank.mp4

Test Plan:
* resize screen to test top bar & menu items
* test workspace toggle and scroll

Reviewers: dkobia, shadowhand, rjmackay

Reviewed By: shadowhand, rjmackay

Subscribers: digitalafrican

Maniphest Tasks: T334, T335, T333

Differential Revision: https://phabricator.ushahidi.com/D158