$FirebaseArray
- $add/$save/$remove throw error if destroyed (test units added)
 - Added $$createRecord
 - Refactored _list to $list
 - moved $notify to _notify
 - started working on comments (more in another PR, didn't want to get this one too big)

 $FirebaseObject
 - added a check before notifying/updating scope

 utils.js
 - refactored updateRecord to return a boolean if anything changed (no need to iterate values again or use angular.equals)
Commented methods in $FirebaseArray. Enhanced _resolveItem to make sure object is a record in the array and to return null instead of undefined.
Merge pull request #341 from firebase/release_0.8_kato

$FirebaseArray