+3. Added a 'M' multi-volume option to dump and restore which enables
+ dumping to multiple files (useful when dumping to an ext2
+ partition to make several dump files in order to bypass the 2GB
+ file size limitation). The 'f' argument is treated as a prefix and
+ the output files will be named <prefix>001, <prefix>002 etc. With
+ the 'M' flag, restore automatically selects the right file without
+ asking to enter a new tape each time.
+