[WFLY-490] first set of tests

Hi Brian,

this is the first set of tests for RBAC I wrote during last week.

In the process, I found some questionable places in the code and marked them with a "TODO". Those are in the first commit. The most important is the fact that multiple roles combination don't work. Maybe you know about the issue, but I really wanted to point that out.

The second commit contains the tests themselves -- a bunch of unit tests for the most important classes in org.jboss.as.controller.access.{permission,rbac} and some integration-level tests for RBAC (basic permission enforcement and response filtering). Those test cases that excersise multiple roles combination are @Ignored for now.

More to come :-)

LT