LU-1538 tests: cleanup test output, acc-small

LU-1538 tests: cleanup test output, acc-small

There are a number of issues observed when running test scripts
on a single-node system.  Several minor cleanups to the test
scripts are also possible (coding style, more clear output, etc):

- sanity.sh test_51ba() should clean up subdirectories even if
  test_51b() failed to create all of the files
- sanity.sh test_61ic() shouldn't print all files to stdout
- running fsx accepts $FSXOPT to allow adding extra test options
- implement acceptance-small.sh via auster, so that we don't have to
  maintain two separate test wrappers, and it would be possible for
  users running acc-sm to upload results to Maloo if they wanted.

Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Change-Id: I8aae9c1af508d8173135f0938e0a26d9731253df
Reviewed-on: http://review.whamcloud.com/3132
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Li Wei <liwei@whamcloud.com>
Reviewed-by: Keith Mannthey <keith@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>