attempt at msvc-10.0 build fix for test_dhy + small documentation note

git-svn-id: http://libtorrent.googlecode.com/svn/trunk@9862 f43f7eb3-cfe1-5f9d-1b5f-e45aa6702bda
attempt to fix linux -fPIC issue in python binding

git-svn-id: http://libtorrent.googlecode.com/svn/trunk@9863 f43f7eb3-cfe1-5f9d-1b5f-e45aa6702bda
fix python binding build on linux for pthread linking

git-svn-id: http://libtorrent.googlecode.com/svn/trunk@9865 f43f7eb3-cfe1-5f9d-1b5f-e45aa6702bda