fix unhandled exception

git-svn-id: https://svn.code.sf.net/p/libtorrent/code/trunk@10016 a83610d8-ad2a-0410-a6ab-fc0612d85776
minor tweak to makefile build system (blindly)

git-svn-id: https://svn.code.sf.net/p/libtorrent/code/trunk@10018 a83610d8-ad2a-0410-a6ab-fc0612d85776
merge build fix from RC_0_16

git-svn-id: https://svn.code.sf.net/p/libtorrent/code/trunk@10019 a83610d8-ad2a-0410-a6ab-fc0612d85776