Allow onChange prop to take the component's internal InputMask as an argument

[mgoldberg524]

It might be helpful to be able to access the component's internal InputMask property as an argument to the onChange handler passed down through props.

For example, one might desire to call mask.getRawValue() from within the handler as the formatting provided by the component might only be needed for display purposes rather than for storage.

[iamdustan]

Thanks @mgoldberg524. Does this still solve a problem you were having? I would like to keep the on* APIs completely analogous with a React Event if possible.

What alternative approaches could allow the consumer access to the raw value as well?