merged http_connection tweak from RC_0_16

git-svn-id: https://svn.code.sf.net/p/libtorrent/code/trunk@9754 a83610d8-ad2a-0410-a6ab-fc0612d85776
reorder the node-list in the DHT traversal algorithm if a node updates its ID

git-svn-id: https://svn.code.sf.net/p/libtorrent/code/trunk@9755 a83610d8-ad2a-0410-a6ab-fc0612d85776
fix ip_voter to detect changing IPs

git-svn-id: https://svn.code.sf.net/p/libtorrent/code/trunk@9758 a83610d8-ad2a-0410-a6ab-fc0612d85776