Rework old XMLRPC code that I stuck into defs.php3 a long time ago,

but never made use of. Moved to its own file (www/xmlrpc.php3.in)
and made to be more like the perl library I did a couple of months ago,
that presents an interface to an sslxmlrpc server, via the sslxmlrpc
client program operating in "raw" mode (takes raw xml on stdin, and
returns raw xml on stdout).

Added ELABINELAB code to nodetipacl.php3 so that you can click on
console icon on an inner emulab web page, and it will ask the outer
emulab sslxmlrpc server for the stuff it needs, and return that to the
user.