- make the output directory if it doesn't exist
- add a forgotten item to the key

- simplify iozone file cleanup a little
- scale each thread's io contribution based on the number of threads
- fix sloppy shell arg passing that accidentally worked

- teach the iozone test to use multiple threads
- add a -e argument to specify the obdecho module by hand
- the echo_filter test performs reads and on the right number of pages
- use more representative io sizes
- use 'getconf PAGE_SIZE' to find the page size on the machine

- run an iostat -x on each block device during each test
- reformat a bit to make room for the iostat reports

- more carefully cleanup to avoid error messages in early cleanup

tests by itself and give detailed results.