LU-1187 lod: Add remote object for DNE

LU-1187 lod: Add remote object for DNE

LOD will do FLD lookup to check whether the object
is for OST or remote MDT object.

Because there are remote object invlove, it might
return some error other than ENOMEM for object allocation.

Signed-off-by: wang di <di.wang@intel.com>
Change-Id: Ie226b3c475524fc7e705665c6200e4c66d50acf0
Reviewed-on: http://review.whamcloud.com/4924
Tested-by: Hudson
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Reviewed-by: Mike Pershin <mike.pershin@intel.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>