FITS: generating send-streams in portable format
This commit adds the command 'zfs fits-send', analogous to zfs send. The
generated send stream is compatible with the stream generated with that
from 'btrfs send' and can in principle easily be received to any filesystem.

*** 70,79 ****
--- 70,80 ----
          zfs_deleg_share_nfs;
          zfs_destroy;
          zfs_destroy_snaps;
          zfs_destroy_snaps_nvl;
          zfs_expand_proplist;
+         zfs_fits_send;
          zfs_get_handle;
          zfs_get_holds;
          zfs_get_name;
          zfs_get_pool_handle;
          zfs_get_user_props;