* Centralize Ticket management of persistent stores
persistence package with Manager & Ticket will handle
all the details about keys, secrets, ticket into cookies,
etc. Persistent stores just need to pass Save, Load &
Clear function handles to the persistent manager now.
* Shift to persistence.Manager wrapping a persistence.Store
* Break up the Redis client builder logic
* Move error messages to Store from Manager
* Convert ticket to private for Manager use only
* Add persistence Manager & ticket tests
* Make a custom MockStore that handles time FastForwards
Felipe Fey
Leandro Lafin
Eduardo Vozniak
Nick Meves