branch for steven solito's patch to make peer connection encryption more generic

git-svn-id: http://libtorrent.googlecode.com/svn@10512 f43f7eb3-cfe1-5f9d-1b5f-e45aa6702bda
apply Steven Siloti's patch to generalize the encryption handler for peer_connections

git-svn-id: http://libtorrent.googlecode.com/svn@10513 f43f7eb3-cfe1-5f9d-1b5f-e45aa6702bda
add asserts to track down issue with new receive_buffer, and fix it. silence some construction-order warnings too

git-svn-id: http://libtorrent.googlecode.com/svn@10514 f43f7eb3-cfe1-5f9d-1b5f-e45aa6702bda