Patch attached with fixes in includes/transcoder.inc for zencoder and other bug fixes

The attached patch makes two changes to code in includes/transcoder.inc.
The first at line 74 rectifies the call by reference error (I forget when this issue occurs but it needs fixing):

public function admin_settings_validate($form, &$form_state) {
return $this->transcoder->admin_settings_validate($form, &$form_state); // removes $ on &$form_state
}

The second fix brings the array_merge() into the loop when searching for video_{transcoder}.inc files.. without this fix, NO transcoder plugins will appear in the list, only those that are present in the /transcoder folder.