config: push plugins.inc to a vital spot to be included once only

src/etc/inc/config.lib.inc

@@ -55,6 +55,14 @@ require_once("legacy_bindings.inc");
 require_once('upgrade_config.inc');
 require_once("certs.inc");
 
+/*
+ * Hook up the plugin system which consists of several low-profile
+ * functions that can be called from within our backend code when
+ * they exist.  The magic here is that if the plugin system is not
+ * required it can be completely disabled by removing plugins.inc.
+ */
+include_once('plugins.inc');
+
 /* make a global alias table (for faster lookups) */
 function alias_make_table($config)
 {
@@ -178,7 +186,6 @@ function write_config($desc = '', $backup = true)
     }
 
     if (function_exists('plugins_interfaces')) {
-        /* only pull plugins if plugins.inc was included before */
         plugins_interfaces();
     }
 

src/etc/inc/services.inc

@@ -2660,7 +2660,6 @@ function services_get()
     );
 
     if (function_exists('plugins_services')) {
-        /* only pull plugins if plugins.inc was included before */
         foreach (plugins_services() as $service) {
             $services[] = $service;
         }

src/etc/inc/system.inc

@@ -783,7 +783,6 @@ function system_syslogd_start()
         $syslogconfs = array();
 
         if (function_exists('plugins_syslog')) {
-            /* only pull plugins if plugins.inc was included before */
             foreach (plugins_syslog() as $plugin_name => $plugin_details) {
                 $syslogconfs[$plugin_name] = $plugin_details;
             }