Refactoring

Renamed getDivElements to getBindableElements. Now can bind to any html
element with the data-bind or datafld attribute.
Modified Start() method to be able to run methods defined outside the
Controller, which should actually be deprecated in the future, but
currently is still there for backwards compatability. The idea is that
any method defined for the MVC object should be able to be called
directly on the object from JavaScript or when bound to an HTML element.

Refactoring of the TODO demo (example).