Add version compare function to setup/index.txt

Okay Ivan, you can "I told you so" now.  I didn't see any major gotchas
to changing the version and was SURE there'd be no reason to write the
convoluted comparison function until after everything was nicely redone
and restructured and whatnot.  Fortunately I only need it in the main
script for now, and will hopefully very soon be able to just load it
from a common function file and use it where needed.

I still don't regret doing it, but all the work I had to do in order to
make sure I didn't screw it up (or rather that I fixed it after screwing
it up) are totally on me.

scripts/a2server-3-sharing.txt

@@ -49,7 +49,7 @@ debianName=$(lsb_release -cs)
 if [[ -f /usr/local/etc/A2SERVER-version ]]; then
 	read a2sVersion </usr/local/etc/A2SERVER-version
 fi
-if [[ "$a2sVersion" != *.*.* || "$a2sVersion" -lt 101 ]]; then
+if [[ "$a2sVersion" != *.*.* && "$a2sVersion" -lt 101 ]]; then
 	echo "A2SERVER: Installing Netatalk (this will take a while)..."
 	# stop Netatalk and samba if running (during upgrade)
 	if [[ $(ps --no-headers -C afpd) ]]; then