added option to deliberately corrupt data from certain peers, to test the case when hash fails occurs
added option to deliberately corrupt data from certain peers, to test the case when hash fails occurs

git-svn-id: 6ed3528c1be4534134272ad6dd050eeaa1f628d3@2446 f43f7eb3-cfe1-5f9d-1b5f-e45aa6702bda

steeve/libtorrent,steeve/libtorrent,steeve/libtorrent,steeve/libtorrent,steeve/libtorrent,steeve/libtorrent