deprecated auto_expand_choker. started factoring out choker logic into its own translation unit (preparing for making it unit testable)

git-svn-id: http://libtorrent.googlecode.com/svn/trunk@10436 f43f7eb3-cfe1-5f9d-1b5f-e45aa6702bda
factored out choke comparison functions into choker.cpp

git-svn-id: http://libtorrent.googlecode.com/svn/trunk@10437 f43f7eb3-cfe1-5f9d-1b5f-e45aa6702bda
moved around some hostname resolver related TODO comment. removed unused hostname query objects

git-svn-id: http://libtorrent.googlecode.com/svn/trunk@10438 f43f7eb3-cfe1-5f9d-1b5f-e45aa6702bda