mig 1.2, new options

[Roland McGrath <roland@frob.com>]

I've added a feature to mig that prints out a list of RPC names and message
ID numbers, as might be useful to process into something that drives rpctrace.

I've declared this version 1.2 of mig, but I haven't uploaded a distribution
anywhere yet.  Anybody can check the mig module out of cvs (see
http://savannah.gnu.org/projects/hurd), run "configure" and "make dist" and
wind up with the same tar file that would be on ftp.gnu.org if one were
there.  I expect Marcus to shortly update the debian/changelog and make a
new debian package, and we'll upload the tar file at the same time.