improve storage unit tests

git-svn-id: https://svn.code.sf.net/p/libtorrent/code/trunk@9769 a83610d8-ad2a-0410-a6ab-fc0612d85776
minor logging improvement

git-svn-id: https://svn.code.sf.net/p/libtorrent/code/trunk@9770 a83610d8-ad2a-0410-a6ab-fc0612d85776
merged changes from RC_0_16

git-svn-id: https://svn.code.sf.net/p/libtorrent/code/trunk@9773 a83610d8-ad2a-0410-a6ab-fc0612d85776