ISPN-4050 + ISPN-3931 Authorization: XML Configuration and SecurityManager integration

ISPN-4050 XML configuration for cache authorization
ISPN-3931 Use a SecurityManager to track security from internal classes

With these two commits we should have all of the authorization framework in place.
In particular ISPN-3931 provides full integration with the JVM SecurityManager, which enables internal Infinispan code to elevate privileges when interacting with code which has been guarded by authorization checks. I have also provided a sample security.policy file which covers the permissions needed by Infinispan and its supporting libraries. I have dumped all permissions into a single "grant codeBase" block. If you believe they should be split per-jar let me know (but it's much more manageable as it is).