String.prototype.ltrim

@Description: Trims all white space off the right side of a string
@File: String/prototype/rtrim.js
@Author: Paul Visco
@Version: 1.0 11/19/07
@Return: String The original text with whitespace removed from the right
@Example:

var myString = 'hello              ';

var newString = myString.rtrim();
//newString = 'hello';