fix bug in peer_connection causing it to not connect when not having metadata

git-svn-id: http://libtorrent.googlecode.com/svn@10384 f43f7eb3-cfe1-5f9d-1b5f-e45aa6702bda
split time_critical and super_seeding tests out of test_swarm

git-svn-id: http://libtorrent.googlecode.com/svn@10385 f43f7eb3-cfe1-5f9d-1b5f-e45aa6702bda