which makes sense when you think about it, so we now increment the instance
when an object is cloned or created.
git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@3107 542714f4-19e9-0310-aa3c-eee0fc999fb1
continue to be constructed without a constructor even if they extend
TrackedObject.
git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@3076 542714f4-19e9-0310-aa3c-eee0fc999fb1