LU-356 adding verbose option in test-framework

LU-356 adding verbose option in test-framework

in test-framework.sh, using the VERBOSE value if it's set by user,
in do_node and do_nodes, fixing the problem of only printing part of
the command during using "lctl mark" to print debug info.

Change-Id: If6444b322849d5f11a8c1f678de0eb7b80398480
Signed-off-by: Hongchao Zhang <hongchao.zhang@whamcloud.com>
Reviewed-on: http://review.whamcloud.com/862
Reviewed-by: Yu Jian <yujian@whamcloud.com>
Tested-by: Hudson
Reviewed-by: Fan Yong <yong.fan@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>