Shopify/batman — pull request #609 by nciagra (2012-12-06 21:14:49+00:00)
Title: Minor Memory Improvements for Bindings and DOM Events

@kristianpd @mattwdh @pushmatrix This gives us ~10% of a reduction in references on views.

There's a few things in here worth looking at.
- Standardisation and consistency to the Binding creation API. It gets used in a few places and now there are specific `BindingDefinition` to make sure bindings are always configured with the correct arguments.
- We also optimize a number of the binding classes by only creating unidirectional bindings as opposed to bidirectional, when the latter simply would not make sense.
- Reductions in the amount of DOM events created and retained.
- The start of converting `on`'s to `once`'s where applicable. Doing this throughout the framework will also drastically reduce the number of event handlers retained indefinitely.

Lots of code, most of it is just moving things around. Let me know if you have questions about where the important parts lie.