reddit.compact: Make mobile toolbar overflow scrollable on touch devices...

Mobile toolbars were wrapping onto a new line.  This patch makes them scrollable via a library called overthrow.  Will work native on IOS devices and possibly mobile chrome.  

https://github.com/filamentgroup/Overthrow

Library has an MIT/BSD license

https://github.com/filamentgroup/Overthrow/blob/master/license.txt