OpportunisticQM moved from core to default plugins.

This makes it easier to disable, but remember that you must then
either enable and maintain queue daemons or disable queueing (and
handle whatever remaining queue items are stored in the database)!

lib/default.php

@@ -294,7 +294,6 @@ $default =
                             'AuthCrypt' => array(),
                             'Cronish' => array(),
                             'LRDD' => array(),
-                            'OpportunisticQM' => array(),
                             'StrictTransportSecurity' => array(),
                         ),
               'default' => array(
@@ -305,6 +304,7 @@ $default =
                             'Event' => array(),
                             'Oembed' => array(),
                             'OpenID' => array(),
+                            'OpportunisticQM' => array(),
                             'Poll' => array(),
                             'QnA' => array(),
                             'SearchSub' => array(),