land bug9972(b1_4_lov_lvb_cleanup) on b_release_1_4_6

land bug9972(b1_4_lov_lvb_cleanup) on b_release_1_4_6

DESCRIPTION: replace loi_rss,loi_mtime,loi_ctime,loi_ctime with struct ost_lvb.
	     on the same time, add obd_merge_lvb(lov_merge_lvb) into obd_ops
	     (lov_obd_ops)
BUG: 9972

Modified Files:
Tag: b_release_1_4_6
 	include/linux/lustre_lib.h include/linux/obd.h
 	include/linux/obd_class.h liblustre/llite_lib.h liblustre/rw.c
 	liblustre/super.c llite/file.c llite/llite_mmap.c llite/rw.c
 	lov/lov_internal.h lov/lov_merge.c lov/lov_obd.c
 	lov/lov_request.c obdclass/lprocfs_status.c
 	obdfilter/filter_lvb.c osc/osc_request.c