Array.prototype.unique

@Description: Removes duplicate values from an array
@File: Array/prototype/unique.js
@Author: Paul Visco
@Version: 1.1 11/19/07
@Return: Array Returns an array of unique values from the original array
@Example:

var myArray = [5, 5, 10, 15];
var answer = myArray.unique();
//answer =[5,10,15];