** Improved the Array.map() method. If more arguments are declared inside the arg block, then it assumes that the self array is an array of arrays (as Array.each assumes from a long time).

Example:
	[[1,2], [3,4]].map{|a,b| a+b}.dump.say;  # => [3, 7] (which is [1+2, 3+4]);

** Added the MultiArray.map() method;

Example:
	MultiArray.new([1,2], [3, 4]).map {|a,b| a+b}.dump.say; # [4, 6] (which is [1+3, 2+4])