Shopify/batman — pull request #550 by terraflubb (2012-09-10 15:56:54+00:00)
Title: Introduce isDirty accessor to models for a neater binding

For convenience, added an accessor to models (along the same lines as isNew) to return if a model is dirty. This is particularly handy for enabling/disabling Update buttons and stuff like that.

`myObject.isDirty` vs `myObject.lifecycle.state | equals 'dirty'`

Is this okay @nciagra and @hornairs?