Remove deprecated code marked for removal in 0.4
selector: desupport `disabled` to reduce code

Use `Selection#allowSelect` instead; serves same purpose
(but is passed a row object and returns inversely)
List / _StoreMixin: Split observe / QueryResults logic from renderArray

* Create _StoreMixin#renderQueryResults for QR/observe logic
* Optimize observer code to not render/push ahead of time, to avoid
  needing to remove later if results are empty or already unrendered
* Make List#renderArray *only* process arrays
* Reduce code in places using renderArray since they no longer need to
  potentially handle promises
* Rename observers to _observers