file.~<rev>~ re-activated

[Andre Spiegel]

Ok, it seems people have lost their zeal in this discussion so I've
re-comitted the easiest solution which most seemed to have agreed
with.  Manual version backups, as ever, are named 

                              file.~<rev>~

while automatic version backups have an additional dot at the end 

                              file.~<rev>.~

I found this easier to read than Stefan's suggestion to put the dot
_before_ the revision.  Although it might be slightly more
difficult or slower to match my pattern, it turns out that the
current value of `auto-mode-alist' actually matches it faster (I'm not
even quite sure how and why it does match Stefan's suggestion at all).

Once again, this is a change in vc-hooks.el and requires a rebuild or
(load "vc-hooks") to become activated.