upgrade via CVS

Simon,

Thank you for contributing the upgrade via CVS instructions to the wiki!
FYI, I've moved them from:

http://openwall.info/wiki/Owl/upgrade

to a new page at:

http://openwall.info/wiki/Owl/cvs

and I've added a link from the "upgrade" page.  My rationale for this is
that this is not a recommended procedure for most users, so I want to
keep the "upgrade" page free from these optional instructions.

I also made some minor edits to your instructions - you could want to
take a look.

Thanks again,

Alexander