Added support for hidden descriptors, with tests
Added the KeyHolder descriptor with tests, also added the store variable to db
Removed support for references in
types, Its buggy; all previous tests still pass
rewrote the phone type to make it simpler
Added support for type checking in keyholder, with unittests
Rewrote the implementation of Typed Collections to re-add
the ability to store the keys of Models automatically. e.g.
TypedList(Charge) will store the key for each charge instead of picking
the Charge object
Wrote conversion routine for Typed Collections that store models
Wrote passing tests for TypedMap
Added tests for Set and List