staging/lustre/layout: introduce new layout for released files

Released files now have a standard layout (with generation, pool, ...)
and a stripe count 0 and lmm_pattern flag LOV_PATTERN_F_RELEASED.

Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-2482
Lustre-change: http://review.whamcloud.com/4816
Signed-off-by: Jinshan Xiong <jinshan.xiong@intel.com>
Signed-off-by: Johann Lombardi <johann.lombardi@intel.com>
Reviewed-by: Keith Mannthey <keith.mannthey@intel.com>
Reviewed-by: Fan Yong <fan.yong@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Peng Tao <tao.peng@emc.com>
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>