LU-3089 tests: Give ZFS more time to complete dd's

Due to LU-2887 and ilk, give zfs more time to do disk transfers.  Also
cleanup test formatting.

Signed-off-by: Nathaniel Clark <nathaniel.l.clark@intel.com>
Change-Id: Ia22f2244ccec552046d2efeaeaa6e2194547c96c
Reviewed-on: http://review.whamcloud.com/6217
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
LU-2930 test: add tests for data version

This patch adds support of dataversion access in
multiop and use it to test dataversion on volatile
file.
It also adds a test in sanity.sh to validate dataversion works as
expected (changes between writes)

Signed-off-by: JC Lafoucriere <jacques-charles.lafoucriere@cea.fr>
Change-Id: I62c2b2124d225331873185d92f5c2404a74b1196
Reviewed-on: http://review.whamcloud.com/5660
Reviewed-by: Faccini Bruno <bruno.faccini@intel.com>
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Johann Lombardi <johann.lombardi@intel.com>