Yet another version of the enter/exit scripts to get DHCP to work both regular- and elabinelab-wise. For regular experiments, nothing has changed. New strategy for inner elab nodes: if we get a reply with dns server 220.127.116.11 (our current indication that the responder is real boss), then we know this interface is the real control net. So we hardwire the speed/duplex on *every other* interface at this time. Also had to resurrect a hack to issue a few tmcc calls before running the sethostname script. Apparently, the first few DNS queries after a speed/duplex change may get lost. This causes tmcd calls to fail occasionally. So make em fail early before we try to do anything important. Yuk, yuk, yuk.