Implement Integers with Commas

, Integers with Commas ,
====================

#### Features
* Allows Integers to optionally include commas
* Integers can either be formatted in the original "123456789" format or "123,456,789"

Examples:
* 1234 :ok:
* 12b4 :no_entry_sign: 
* 1,000,000 :ok:
* 10,00,000,000 :no_entry_sign: 
So, I originally tried to implement this without including the `for stringPart in lutil.splitString(inputString)` loop. I don't understand why, but it was making specs for Date fail. Check it out:

![screen shot 2014-07-15 at 3 14 02 am](https://cloud.githubusercontent.com/assets/2609819/3581643/aa46c130-0bef-11e4-9ee9-ee0ce49a8bb9.png)

I'm confused by this, because it seems to me that the callback should have been called - and in all of the cases for Integer, it is. Why doesn't it work for Date if you don't include the `lutil.splitString` loop?

Looking at the implementation of `lutil.splitString`, it seems like it returns a list of all substrings of `inputString`. Is this correct?

I thought it would be an optimization to take this out, because I didn't think testing all substrings really did anything. A quick explanation would be awesome!