TOPS-20 renamef

[JONL at MIT-MC (Jon L White)]

1) RENAMEF apparently fails to do the corresponding CNAMEF as is
   done on the ITS version
2) RENAMEF fails to accept namelist, but barfs about illegal 
   source/destination designator
3) If one does a RENAMEF while the file is open, then subsequent calls
   to TRUENAME on the open file-object re4sult is illegal op code execution.