fix unit test web server for tracker announces

git-svn-id: https://svn.code.sf.net/p/libtorrent/code/trunk@9110 a83610d8-ad2a-0410-a6ab-fc0612d85776
attempt to fix test http proxy to handle EAGAIN errors

git-svn-id: https://svn.code.sf.net/p/libtorrent/code/trunk@9111 a83610d8-ad2a-0410-a6ab-fc0612d85776
proper fix for unit test http proxy handling EAGAIN

git-svn-id: https://svn.code.sf.net/p/libtorrent/code/trunk@9112 a83610d8-ad2a-0410-a6ab-fc0612d85776
improve error message for tracker_error_alert. various smaller attempts at making the unit tests more reliable

git-svn-id: https://svn.code.sf.net/p/libtorrent/code/trunk@9115 a83610d8-ad2a-0410-a6ab-fc0612d85776
fix deprecation warning

git-svn-id: https://svn.code.sf.net/p/libtorrent/code/trunk@9116 a83610d8-ad2a-0410-a6ab-fc0612d85776