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.

@@ -589,10 +589,12 @@
 
 typedef boolean_t (snapfilter_cb_t)(zfs_handle_t *, void *);
 
 extern int zfs_send(zfs_handle_t *, const char *, const char *,
     sendflags_t *, int, snapfilter_cb_t, void *, nvlist_t **);
+extern int zfs_fits_send(zfs_handle_t *, const char *, const char *,
+    sendflags_t *, int, snapfilter_cb_t, void *);
 
 extern int zfs_promote(zfs_handle_t *);
 extern int zfs_hold(zfs_handle_t *, const char *, const char *, boolean_t,
     boolean_t, boolean_t, int, uint64_t, uint64_t);
 extern int zfs_release(zfs_handle_t *, const char *, const char *, boolean_t);