use apple's common crypto for sha-1 and add missing source file

git-svn-id: https://svn.code.sf.net/p/libtorrent/code/trunk@8378 a83610d8-ad2a-0410-a6ab-fc0612d85776
extend move_storage functionality to have more flexible behavior

git-svn-id: https://svn.code.sf.net/p/libtorrent/code/trunk@8379 a83610d8-ad2a-0410-a6ab-fc0612d85776