add include_plugin function for optoinal plugins

JohnDoh

2014-08-16 4eee212883b34e1ca7cfb9466580ff20dca5c979

 program/lib/Roundcube/rcube_message_header.php

@@ -225,8 +225,16 @@
        }

        if ($decode) {
            $value = rcube_mime::decode_header($value, $this->charset);
            $value = rcube_charset::clean($value);
            if (is_array($value)) {
                foreach ($value as $key => $val) {
                    $value[$key] = rcube_mime::decode_header($val, $this->charset);
                    $value[$key] = rcube_charset::clean($val);
                }
            }
            else {
                $value = rcube_mime::decode_header($value, $this->charset);
                $value = rcube_charset::clean($value);
            }
        }

        return $value;