Change to sarge version numbering code

[Julian Gilbey <jdg@polya.uklinux.net>]

While tidying up the common.variables code in tetex-bin, I changed the
code which computes the sarge backport version number.  The key diff
is effectively:

-    ($SARGEVERSION=$VERSION) =~ s/^(.*-)$rev([^\-]*)$/$1${sarge_rev}bpo1/;
+    ($SARGEVERSION=$VERSION) =~ s/^(.*-)$rev([^\-]*)$/$1${sarge_rev}${2}bpo1/;

meaning that NMUs, eg -14.2, will become sarge version -13.2bpo1
instead of -13bpo1.  This is the correct behaviour, I would suggest.

   Julian