improve node-id generation for DHT maintanence calls

git-svn-id: http://libtorrent.googlecode.com/svn@10462 f43f7eb3-cfe1-5f9d-1b5f-e45aa6702bda
improve DHT bootstrapping and periodic refresh

git-svn-id: http://libtorrent.googlecode.com/svn@10463 f43f7eb3-cfe1-5f9d-1b5f-e45aa6702bda
fix dht log parsing script

git-svn-id: http://libtorrent.googlecode.com/svn@10464 f43f7eb3-cfe1-5f9d-1b5f-e45aa6702bda