Adding ORDER BY so device groups are sorted by name instead of creation.

Currently the function for retrieving device_groups returns rows in the order
in which they were created.  This causes the WebUI to display is a semi-random
order.  This patch causes the devices to be sorted by name which makes the
group lists easier to navigate.

includes/device-groups.inc.php

@@ -92,7 +92,7 @@ function GetDevicesFromGroup($group_id) {
  * @return array
  */
 function GetDeviceGroups() {
-    return dbFetchRows('SELECT * FROM device_groups');
+    return dbFetchRows('SELECT * FROM device_groups ORDER BY name');
 
 }//end GetDeviceGroups()