Integrate JGroups with core AS security infrastructure

Container task for better integrating JGroups security with overall AS security. The basic concept is the various security aware aspects of JGroups will expose an SPI, and the AS can create implementations of those SPIs that integrate with the AS security realms. The AS JGroups subsystem will inject the implementation into the JGroups runtime components.

Subtasks are for the various aspects. These can be done separately but a common overall design should be created to ensure a consistent approach is taken.