/* applyMixin
Applies a mixin to the given parameter by using underscores extend function.

Parameters:
(Barefoot.Router) backboneRouter - The router to apply the mixin
(Object) - The mixin to apply

Returns:
A router object with the given mixin applied.
function applyMixin(backboneRouter, mixin) {
	var Router = backboneRouter.extend({});
	_.extend(Router.prototype, mixin);
	return Router;
}