Override Marionette Views to integrate incremental-dom

[ahumphreys87]

Incremental DOM rendering has many performance benefits over marionette's standard approach. We should look to override the render method of each marionette view to render using incremental-dom.

[ ] View - render.
[ ] CollectionView - render, filtering (sorting can be removed as you may as well just re-render).
[ ] LayoutView - render, attach regions to elementPlaceholders.
[ ] ItemView - render.

We will make use of the handlebars-idom convertor here: https://github.com/ahumphreys87/handlebars-idom