fix build error with msvc10

git-svn-id: svn://svn.code.sf.net/p/libtorrent/code@10335 a83610d8-ad2a-0410-a6ab-fc0612d85776
merge changes from RC_1_0

git-svn-id: svn://svn.code.sf.net/p/libtorrent/code@10336 a83610d8-ad2a-0410-a6ab-fc0612d85776