Fix three fatal errors when posting from 0.9.x:

* OMB remote updates were trying to load nonexistent Laconica_OMB_Service_Consumer class -- fixed to StatusNet_OMB_Service_Consumer. Regression caused during libomb merge.
* Twitter processing was still being queued from core when no twitter plugin was present, which triggered an exception from UnqueueHandler; leftover code from before the plugin extraction.
* UnqueueHandler's exception caused a fatal error instead because it was missing the "new" keyword. Wouldn't have been seen when testing with the plugin enabled.

lib/util.php

@@ -906,7 +906,6 @@ function common_broadcast_notice($notice, $remote=false)
 function common_enqueue_notice($notice)
 {
     static $localTransports = array('omb',
-                                    'twitter',
                                     'facebook',
                                     'ping');