Handle Multiple Number Groupings

Our Globalization Engineering team at PayPal found a bug that is affecting those in India. Since the number grouping "#,##,###" isn't supported, our team found it was necessary to put in a bit of time and development to support users in India. Please see <b>Indian comma placement> found under <a href="http://en.wikipedia.org/wiki/Indian_rupee">Wikipedia's Indian rupee</a>.

The pull request includes code development and tests that supports (1) the Indian comma placement for the number grouping "#,##,###"; and (2) other future number groupings. The hope for (2) is that regardless of how absurd the number grouping might turn out, it will be supported in Google Closure.

Please let me, <b>John Vu<b>, at <a href="mailto:jovu@paypal.com">jovu@paypal.com</a> know if you have any questions.

P.S. This is my first time contributing to an open-source project so please let me know if there's anything else I should do aside from your <a href="https://github.com/google/closure-library/blob/master/CONTRIBUTING">guidelines for contributing</a>.