Adds keyboard event handling to UI controls and containers.
Fixes tab key navigation.
Fixes a memory leak in Theme.cpp.
Merge branch 'next' of https://github.com/blackberry/GamePlay into next
Fixes some buggy tab and arrow key behaviour.
Fix Slider key event handling for Mac OS.
Merge pull request #999 from ablake/next

Keyboard event handling for UI controls and containers.
Adds raw sensor API for distinguishing acceleration from rotation rate. Part 3 of #835.