Reimplement EAS contacts sync to work w/ new system facilities

* Modify to work with ContactsProvider2
* Modify to work with system AccountManager
* Modify to work with system SyncManager (for triggering user-change syncs)
* Sync server->client for adds/deletes implemented (CP2 doesn't handle delete yet)
* Sync server->client changes handled efficiently (only write changes)
* Some fields still not handled
* Rewrote most of the CPO code to handle server->client changes
* Sync client->server works for supported fields
14 files changed