Merge pull request #8145 from davidflanagan/bug803809

Bug 803809 - pan homescreen based on predicted future motion r=crdlc,cjones,vingtetun(cherry picked from commit 9202b3c1567bd99898ed7a136348637d8a630e63)

Conflicts:
	apps/homescreen/js/grid.js
	build/applications-data.js