GNUnet 0.4.2 released

This is, again, mostly a bugfix release. The bugs were mostly in the area of 
too much (useless) traffic being generated (looping queries, far too frequent 
(attempts to do) key exchanges). There are three main new features:

* trusted networks for the TCP port. gnunetd will refuse connections from
   client applications (gnunet-insert/gnunet-search/etc.) if they are not on
   a trusted network (localhost by default). Before 0.4.2, you had to firewall
   the TCP port to achieve this.
* DNS lookup for NAT boxes that have a dynamic IP (if you have a fixed 
   IP or are not behind a NAT box, this does not matter).
* gnunet-stats, a new tool to display statistics about the node, informative
   and helpful for debugging :-) 

The protocol is 100% compatible with the previous version, but an upgrade is 
highly recommented to reduce traffic.

Christian