Added P4SVRPORT to use to make the server listen on just the port number.
Changed P4PORT to include the hostname to eliminate a bug where the ticket is not
issued by the master as it should be when rpl.forward.login is set up.
Created a p4login_master and updated appropriate scripts to use it. This actually
isn't necessary with the change to include the hostname in P4PORT since the ticket
will be valid on all servers in the group, but this covers configurations that aren't
using rpl.forward.login.