improve debug output from test_tracker

git-svn-id: http://libtorrent.googlecode.com/svn/trunk@9803 f43f7eb3-cfe1-5f9d-1b5f-e45aa6702bda
improve regression testing framework

git-svn-id: http://libtorrent.googlecode.com/svn/trunk@9804 f43f7eb3-cfe1-5f9d-1b5f-e45aa6702bda