Use a custom DNS library to resolve SRV records

Hi,

As said I've once written a small DNS lib to help my XMPP lib. I've just ported it over and would like to see it merged. It can parse A, AAAA, NS and SRV records.

I've also added code that will populate the namePort bundle with a randomized (based on priority/weight rules) server list (name0:port0 ... nameN:portN). This could be used to fall back to alternate servers.

I've tried it with jabber.ccc.de and it works great.