code review request : RegistryImpl clean up (7102369)

[Seán Coffey]

Some clean up of the RMI RegistryImpl class is necessary after late changes
made in the last set of udpate releases.

This is a webrev to bring the code into sync with 6uX, 7uX.
The java.rmi.server.codebase property no longer needs to be parsed by 
the registryImpl.

webrev  : http://cr.openjdk.java.net/~coffeys/webrev.rmi.6open/
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7102369

Regards,
Sean.