 - encapsulate all logic for iterating over CCache contents into a CCacheIter class  - use the CCacheIter class to fill out the mapping protocol on the CCache class
 - encapsulate all logic for iterating over CCache contents into a CCacheIter class
 - use the CCacheIter class to fill out the mapping protocol on the CCache class

cbenning/python-krbV,cbenning/python-krbV,cbenning/python-krbV