Bug 990028 - [Home2] App and Bookmark Icon Deletion r=me

https://bugzilla.mozilla.org/show_bug.cgi?id=990028

Note: Due to time sensitivity, homescreen2 work is currently landing un-reviewed for code within test_apps. A full review pass will happen before merging into apps/. If you have any drive-by comments/concerns please leave them and I will address them.