Utility to create pnSeed array

contrib/seeds/README

@@ -0,0 +1,9 @@
+Utility to generate the pnSeed[] array that is compiled into the client
+(see src/net.cpp).
+
+The 600 seeds compiled into the 0.8 release were created from sipa's DNS seed data, like this:
+
+curl -s http://bitcoin.sipa.be/seeds.txt | head -1000 | makeseeds.py
+
+The input to makeseeds.py is assumed to be approximately sorted from most-reliable to least-reliable,
+with IP:port first on each line (lines that don't match IPv4:port are ignored).