Emit "mounted" event on child views

According to [this](https://github.com/ripplejs/ripple/tree/master/docs#lifecycle-events) documentation, a `mounted` event should be triggered, each time a view enters the DOM.

This implies, that each time a view is mounted, each of its child views (attached via `.compose()`) should emit a `mounted` event as well.

Currently this is not the case. I will look into this (I guess it should be fairly straightforward to implement this) and see if I can provide a pull-request, but for now I wanted to know your opinions of this, and if this would be indeed the correct, expected behavior.

Sorry about issue #30, I would have preferred to attach the PR to it, but apparently I am not quite familiar enough with github to do that. Therefore I closed #30 and continue here.