Array.lua v1.2.3

A small library with useful methods to handle Lua's table when it's working like an Array.

What's new from Array.lua v1.2.2?

• Added array.diff function. It returns a new table with the items which exist only in the first table
• Updated array.concat function. Now it's returning a new table instead of changes the previous object passed by parameter
• Update the name of the following methods array.deep_copy and array.shallow_copy. Before they were in camel case.