Node.js module-style code support

[leggetter]

As we all know, this is a priority.

We want to be able to write code so that the auto-generated classes look as follows:

var br = require( 'br' );

var Property = require( 'br/presenter/Property');
var PresentationModel = require( 'br/presenter/PresentationModel' );

function ExampleClass() {
  this.message = new Property( "Hello World!" );
};
br.extend(ExampleClass, PresentationModel);

ExampleClass.prototype.buttonClicked = function() {
  console.log( 'button clicked' );
};

Relies on #227 and #230.