Performance optimations

A whole slew of macro and micro optimizations. These are generally non breaking but there are a few changes that may break some workflows.

1. Users building with lumbar who desire the forms feature must include the thorax-form mixin
2. The `helper:$name` event has been removed. Users should bind to the `helper` event and check the name parameter that they wish to examine.
3. `_.uniqueId` no longer uses global variables for tracking state. Instead callers must call `_resetIdCounter` when wishing to modify that behavior.
4. `context` no longer clones the model attributes so callers need to take care to not modify the returned value.
![](http://846cf0b556e2091331f7-8440970b8caee5315b172abf77b42b06.r10.cf1.rackcdn.com/costumes/images/characters/dr-seuss/thing1-thing2/cat-in-the-hat-08.jpg)