LU-3397 lprocfs: create "export" /proc file on server

LU-3397 lprocfs: create "export" /proc file on server

Similar to the "import" file on the client for each client-to-server
connection, it would be useful to have a file on the server in the
per-nid directory obdfilter/*/exports/$NID/export. This contains
export connection information as in the "import" file, like:
 a793e354-49c0-aa11-8c4f-a4f2b1a1a92b:
     name: MGS
     client: 10.211.55.10@tcp
     connect_flags: [ version, barrier, adaptive_timeouts, ... ]
     connect_data:
        flags: 0x2000011005002020
        instance: 0
        target_version: 2.10.51.0
        export_flags: [ ... ]

Also, sanity.sh test_0d is added to verify this patch.

Signed-off-by: Emoly Liu <emoly.liu@intel.com>
Signed-off-by: James Simmons <uja.ornl@gmail.com>
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Change-Id: I60896090e3a8ad872141a8d4299f0698f0a5636a
Reviewed-on: https://review.whamcloud.com/6713
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Nathaniel Clark <nathaniel.l.clark@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>