Enable type-aware data-binding

This PR enables type-aware data-binding by adding a "typeOverride" attribute to the two-way binding events option hash.

It properly converts string data captured from a "number" input to a JSON number object on-the-fly, before the data is improperly sent over the wire as a string.

If you need me to fill out a contributor agreement, please let me know (this will not be my last PR).