Log Message:
Update to 21.0 and mark as BROKEN.

* Introduce WEBRTC patches for FreeBSD, this patches are not work for
  NetBSD.
* When firefox/xulrunner-22.0 is released, I will check the functionality
  of xulrunner package again.
* Patches and dist.mk are used by www/firefox.
* Take MAINATINERship.