1) Updating a group without changing the avatar will keep that
avatar
2) Prohibit adding non-push users to an existing push group
3) Add Android contacts to the same database. Takes a small amount
more time and memory, but allows queries to not be a hack, and
enables us to dedupe numbers in JB and higher devices.
// FREEBIE
* unify single and multi contact selection activities
* follow android listview design recommendations more closely
* add contact photos to selection
* change indicator for push to be more obvious
* cache circle-cropped bitmaps
* dedupe numbers when contact has multiple of same phone number
// FREEBIE
