merged changes from RC_1_0

git-svn-id: http://svn.code.sf.net/p/libtorrent/code/trunk@10389 a83610d8-ad2a-0410-a6ab-fc0612d85776
fix issue when hash checking files resulting in a short read

git-svn-id: http://svn.code.sf.net/p/libtorrent/code/trunk@10390 a83610d8-ad2a-0410-a6ab-fc0612d85776