[Building Sakai] Help testing realm grant caching (KNL-600)

[David Horwitz]

Hi All,

This is a request to help test a new cache on realm grants in the
AuthzService - analysis revelaed that under certain conditions these
could be re queried in rapid succession. Testing as a single user
visiting site info and a couple of other tools generated in the region
of 9 hits and a success rate of over 90%.

Due to the critical importance of Authz I would appreciate some more
eyes to review the patch attached to the ticket.

D