Document change to update_attribute

Author: bkeepers

UPGRADES

@@ -1,3 +1,6 @@
+0.10 => 0.11
+  * #update_attribute now ignores attr_accessible and attr_protected
+
 0.9 => 0.10
   * Using String IDs are no longer supported. If you are declaring your own ID, ensure it is an ObjectId, and set the default
       key :_id, ObjectId, :default => lambda { BSON::ObjectId.new }