Merge "[key event focus handling] Cleanup/Refactor/Feature 1) Focus navigation handli...

Merge "[key event focus handling] Cleanup/Refactor/Feature 1) Focus navigation handling is refactored to Focus utility class. New 2 step dpad navigation algorithm is inside Focus class 2) Introduced a map (or matrix) that indicates where sparse icons are located inside a grid. This enables getting rid of the icon sorting logic which was costly. 3) Unified all the dpad handling logic inside the handleXXKeyEvent methods 4) DOWN/UP key will allow navigation between workspace icons and the hotseat 5) Folder icons allow DOWN/UP to navigate to the title" into ub-launcher3-master