These are the files I pulled out of cache_tests.rb, they're not wired
up yet.  But worth having in git so they don't get lost.
Merge branch 'devel' of git://github.com/snitm/thinp-test-suite
Merge branch 'devel' of git://github.com/snitm/thinp-test-suite
add test_writethrough_ext4_uuids_match

With this test I was unable to reproduce Darrick's report:
http://www.redhat.com/archives/dm-devel/2013-March/msg00083.html