Make version semantic (Closes #49)

What's still missing from this is a version comparison mechanism.  The
reason why it is missing is that we only use this in one place at the
moment, and if you have a version string that is not three digits, your
version is recent enough.  This means we can save this for when there
are a common functions script to import and make the comparisons for us
without code duplication.

scripts/a2server-3-sharing.txt

@@ -56,9 +56,10 @@ if [[ $debianVersion ]]; then
 fi
 
 # skip this if already done
-if [[ -f /usr/local/etc/A2SERVER-version && $(head -c 3 /usr/local/etc/A2SERVER-version) -ge 101 ]]; then
-	echo "A2SERVER: Netatalk is already installed."
-else
+if [[ -f /usr/local/etc/A2SERVER-version ]]; then
+	read a2sVersion </usr/local/etc/A2SERVER-version
+fi
+if [[ $a2sVersion = *.*.* || $a2sVersion -ge 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
@@ -176,7 +177,10 @@ else
 		cd
 		rm -rf /tmp/netatalk
 	fi
+else
+	echo "A2SERVER: Netatalk is already installed."
 fi
+unset a2sVersion
 
 # --- Install MacIPgw
 if ! hash macipgw &>/dev/null; then

setup/index.txt

@@ -9,7 +9,7 @@
 # to download and execute, type:
 # wget ivanx.com/a2server/setup; source setup
 
-a2serverVersion="151"
+a2serverVersion="1.5.1"
 
 # Ensure URL we'll use ends in a /
 case "$A2SERVER_SCRIPT_URL" in
@@ -35,8 +35,12 @@ if lsb_release -a 2> /dev/null | grep -q 'Distributor ID:.Debian'; then
 	fi
 fi
 
-if [ -f /usr/local/etc/A2SERVER-version ]; then
-	installedVersion="$(cat /usr/local/etc/A2SERVER-version)"
+if [[ -f /usr/local/etc/A2SERVER-version ]]; then
+	read installedVersion </usr/local/etc/A2SERVER-version
+    if [[ $installedVersion != *.*.* ]]; then
+		# Deal with old three-digit version
+        installedVersion="${installedVersion:0:1}.${installedVersion:1:1}.${installedVersion:2}"
+    fi
 fi
 echo "A2SERVER version available: $a2serverVersion"
 echo "A2SERVER version installed: ${installedVersion:=None}"

update/index.txt

@@ -10,9 +10,13 @@ esac
 currentVersion=$(wget -qO- "${scriptURL}setup/index.txt" | grep '^a2serverVersion' | cut -d '"' -f 2)
 
 if [[ -f /usr/local/etc/A2SERVER-version ]]; then
-	installedVersion=$(cat /usr/local/etc/A2SERVER-version)
+	read installedVersion </usr/local/etc/A2SERVER-version
+    if [[ $installedVersion != *.*.* ]]; then
+		# Deal with old three-digit version
+        installedVersion="${installedVersion:0:1}.${installedVersion:1:1}.${installedVersion:2}"
+    fi
 else
-	installedVersion=100
+	installedVersion="1.0.0"
 fi
 
 autoAnswerYes=