Change the way that elabinelab communicates with the outer emulab.
Instead of passing along a set of arguments that needs to be turned into command line arguments to the proxy, pass along an xmldoc representing the arguments. This xmldoc is passed through the rpc server to the snmpit proxy, where it reconstructs the arguments. This avoids all that cruftiness in the rpc server (also error prone) and make it easier to add new remote methods, say for supporting eventual elabibelab firewalls. Note that there are currently two versions of the proxy and two methods in the rpc server, so that existing emulabs will work. I also added support for port enable/disable/etc from the inner elab. There is also the beginning of firewall support. I pass the stack module argument along, but currently not actually doing control stack operations from the proxy. Needs more work. Oh, I copied the cvs repo file for the original proxy so that we do not lose the cvs history. See corresponding commitlog for snmpit for description of other changes.