improve robustness of web_seed unit tests

git-svn-id: http://libtorrent.googlecode.com/svn@9797 f43f7eb3-cfe1-5f9d-1b5f-e45aa6702bda
merged changes from trunk

git-svn-id: http://libtorrent.googlecode.com/svn@9798 f43f7eb3-cfe1-5f9d-1b5f-e45aa6702bda
attempt at fixing i2p bug. introduce i2p_alert to report i2p errors

git-svn-id: http://libtorrent.googlecode.com/svn@9799 f43f7eb3-cfe1-5f9d-1b5f-e45aa6702bda
merged i2p_alert fix from RC_0_16

git-svn-id: http://libtorrent.googlecode.com/svn@9800 f43f7eb3-cfe1-5f9d-1b5f-e45aa6702bda