I added a Token object that takes an AccessInfo in the constructor.  Hashing of the PKI token is performed in that Token class, this also centralized the hashing code.

The code has been tested the code with different combination of token format and Keystone version:  v2/UUID, v2/PKI, v3/UUID/single domain, v3/PKI/single domain, v3/UUID/multi-domain and v3/PKI/multi-domain.