New -osirrox option sparse= controls extraction into sparse files

xorriso/xorriso_private.h

@@ -864,6 +864,9 @@ struct XorrisO { /* the global context of xorriso */
  int show_hfs_cmd_count;
  char **show_hfs_cmds;
 
+ /* Extraction to sparse files */
+ off_t sparse_min_gap;
+
  /* result (stdout, R: ) */
  char result_line[10*SfileadrL];
  int result_line_counter;