Extend the media names table & improve tftp help
While this is related to RiscOS/Sources/Lib/TCPIPLibs!1 (merged) it's not actually dependent on it as the strings are just in a big array initialiser.
Also - beware that there's a second (local) VersionNum file for showstat, which I've manually incremented, which is not the same as the parent one for the InetRes component more generally.