make use of stopService loader function in rpm preun template

- update rpm preun-template to match the rpm postinst-template by making use of the `stopService` loader function
- make systemv loader-functions consistent in use of `hash` builtin and redirections, and tidy up language in warning message

src/main/resources/com/typesafe/sbt/packager/archetypes/java_server/rpm/preun-template

@@ -1,5 +1,3 @@
 ${{loader-functions}}
 
-# Halting ${{app_name}}
-echo "Shutdown ${{app_name}}"
-service ${{app_name}} stop || echo "Could not stop ${{app_name}}"
+stopService ${{app_name}} || echo "Could not stop ${{app_name}}"

src/main/resources/com/typesafe/sbt/packager/archetypes/java_server/systemloader/systemv/loader-functions

@@ -8,13 +8,13 @@ startService() {
 	echo "Adding $app_name to autostart using update-rc.d"
 	update-rc.d $app_name defaults
 	service $app_name start
-    elif hash chkconfig 2>/dev/null; then
+    elif hash chkconfig >/dev/null 2>&1; then
 	echo "Adding $app_name to autostart using chkconfig"
 	chkconfig --add ${{app_name}}
 	chkconfig $app_name on
 	service $app_name start
     else
-	echo "WARNING: Could not put $app_name in autostart: update-rc and chkconfig or found!"
+	echo "WARNING: Could not add $app_name to autostart: neither update-rc nor chkconfig found!"
     fi
 }
 
@@ -28,13 +28,13 @@ stopService() {
 	echo "Removing $app_name from autostart using update-rc.d"
 	update-rc.d -f $app_name remove
 	service $app_name stop
-    elif chkconfig 2>/dev/null; then
+    elif hash chkconfig >/dev/null 2>&1; then
 	echo "Removing $app_name from autostart using chkconfig"
 	chkconfig $app_name off
 	chkconfig --del $app_name
 	service $app_name stop
     else
-	echo "WARNING: Could not put $app_name in autostart: update-rc or chkconfig not found!"
+	echo "WARNING: Could not remove $app_name from autostart: neither update-rc nor chkconfig found!"
     fi
 
 }