Allow passing single argument to dush()

[tunnckoCore]

Which will be used to extend the returned object. Inheritance.

For example

var app = dush({
  foo: 'bar'
})

console.log(app.foo) // => 'bar'
console.log(app.on) // => function

[tunnckoCore]

Actually, "plugins" would fix this too. And will allow for more customization, for example wrapper for dom usage.