Remove the $Revision$ expansions as I'm no longer using subversion.
There doesn't seem to be any agreement about what tag to use between
different source versioning system, so I'm scrapping that part of the
file comments entirely.  No $Revision$, no $Id$, no nothing.  Count on
your software versioning system to keep track of it regardless of what
you do with the source code.  It's the *revisioning* system that matters
anyhow -- if in doubt, refresh from the source.