Inheritance.js

// allow object inheritance
Object.extends = function (ctor, superCtor) {
	// collect objects already on the prototype to "save" them
	var descriptors = {};

	// copy properties from old prototype
	Object.getOwnPropertyNames(ctor.prototype).forEach(function (propertyName) {
		descriptors[propertyName] = Object.getOwnPropertyDescriptor(ctor.prototype, propertyName);
	}, this);

	// proto
	var newProto = Object.create(superCtor.prototype, descriptors);

	ctor.prototype = newProto;
	ctor.$super = superCtor;
};