Modified todo presenter to rely more on reloading
Modified todo presenter to rely more on reloading

* Added a filter state to the todo presenter
* Instead of manually inserting and removing individual task items and
  trying to keep the DOM in sync with the model, let the list
  just re-render itself upon adds, removes, and toggles.
* The nice side effect of this is that adds and toggles automatically
  respect the current filter state, which better mimicks all otehr
  todomvc implementations.

nippur72/riotjs-todomvc,nippur72/riotjs-todomvc,nippur72/riotjs-todomvc,tpphu/riotjs-todomvc,3den/riotjs-todomvc,tpphu/riotjs-todomvc