Updating all Memcached_DataObject extended classes to Managed_DataObject

Updating all Memcached_DataObject extended classes to Managed_DataObject

In some brief tests, this causes no problems.

In this state however, you would need to modify DB_DataObject to have a static declaration of staticget (and probably pkeyGet). The next commit will change the staticGet overload to a unique function name (like getKV for getKeyValue), which means we can properly call the function by PHP Strict Standards.