MARPLOT BINARY FILE FORMAT: LYR (layer information) files

	layer name (32 chars)
	layer's world rectangle on this map
	    low-long + 180000000 (long)
	    low-lat + 90000000 (long)
	    hi-long + 180000000 (long)
	    hi-lat + 90000000 (long)
   	number of objects on layer of this map (long)