updates to vss2cvs.pl (VSS to CVS conversion perl script)

[Laine Stump]

I've spent some time in the last few weeks hacking at Jerry Nairn's
vss2cvs.pl script (and a bit on massagecomments.pl), and have made
some changes that I think others will find useful while converting
from VSS to CVS. You can find my modified versions at:

        http://www.laine.org/cvs/vss2cvs

Look in the file README for details of the changes. A short summary of
the important changes:

1) vss2cvs.pl is now re-startable, so you can re-run it after changes
   have been checked in to VSS (as long as you've kept CVS read-only),
   rather than being forced to redo the conversion from scratch.  This
   can significantly shorten the downtime when you do the final
   switchover.  massagecomments.pl can also now be re-run on a ,v file
   without destroying it, for the same reason.

2) Options processing is now more flexible, and easier to understand.

3) VSS branches (at least the way *our* VSS people do branches) are
   now handled. See the README for details.

At some point maybe these scripts will become useful enough that they
should be put into the cvs contrib directory... (I know they're
certainly useful to me!)

P.S. Thanks for posting your scripts, Jerry. They've been a real
lifesaver!