LU-590 tests: obdfilter-survey.sh fails test 2a.

LU-590 tests: obdfilter-survey.sh fails test 2a.

obdfilter-survey.sh fails to connect during test 2a.
Interruption to and restart of test leads to a panic.
This patch sets correct target for netdisk case, allows to
handle signals in test scripts, sets correct parameters for
obdfilter-survey cleanup.

Xyratex-bug-id: MRP-118
Change-Id: I057610ba51e9a9afb704b4467b8600fd61652a71
Signed-off-by: Andriy Skulysh <Andriy_Skulysh@xyratex.com>
Reviewed-by: Alexey Lyashkov <alexey_lyashkov@xyratex.com>
Reviewed-on: http://review.whamcloud.com/1288
Tested-by: Hudson
Reviewed-by: Yu Jian <yujian@whamcloud.com>
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>