def processing_hint_str number, level
			total = (@ts.tile_size(level) ** 2).to_s
			now   = (number + 1).to_s.rjust(total.length, " ")
			"#{now}/#{total}"
		end
def processing_hint_str number, level
			total = (@ts.tile_size(level) ** 2).to_s
			now   = (number + 1).to_s.rjust(total.length, " ")
			"#{now}/#{total}"
		end
Format a beautiful hint string