Fix Remoting documentation in AS5 Administration And Configuration Guide

Section 11.1. "Summary of JBoss Remoting Features" is somewhat out of date, and Section 11.2. "JBoss Remoting Configuration in the JBoss Application Server" is wrong.

It's still unclear whether Remoting 3 will be ready for AS 5.1.0. If not, then I would be happy to fix the doc, if I knew where it is. If Remoting 3 ships in time, then I'm sure someone from Remoting can supply the appropriate information.