fix boost-build feature name clash with new boost.coroutine Jamfile

git-svn-id: svn://svn.code.sf.net/p/libtorrent/code/branches/RC_1_0@10474 a83610d8-ad2a-0410-a6ab-fc0612d85776
fix bug in interest calculation, causing premature disconnects

git-svn-id: svn://svn.code.sf.net/p/libtorrent/code/branches/RC_1_0@10475 a83610d8-ad2a-0410-a6ab-fc0612d85776