Check for universal controller only detects current version

Currently the check in AvatarService for whether a controller is universal compares the controller's address with that of the UController known to the executing version of arc.js. Therefore the check is not aware of other versions of UController, neither previous nor future. In those cases it would incorrectly identify a UController as a Controller.

We need to have a mechanism whereby we can reliably determine, given an address, whether it is a Controller or UController.

Could be related to #8, but that would only provide information about past deployments. Ideally there would be another way to so this.

Start in AvatarService, where the universal-controller check compares an address with the UController known to the executing arc.js version. Review the relationship to issue #8 and determine how Controller and UController addresses could be distinguished across previous and future versions; done means the classification no longer depends only on the current version.

Written by the indexing model from the issue text.