LU-1187 utils: add lfs setdirstripe/getdirstripe

1.Add lfs setdirstripe/mkdir/getdirstripe to create
remote directory.

2.Add lfs rm_entry to just remove the entry of remote
directory.

Change-Id: Idaecfbb9dd97e3ae9fbc70e5b902a91a7b2ed18e
Signed-off-by: Wang Di <di.wang@intel.com>
Reviewed-on: http://review.whamcloud.com/4341
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>