documentcloud/backbone — pull request #1618 by braddunbar (2012-09-04 16:23:19+00:00)
Title: Fix #1478 - Attribute changes to original value should be silent.

* Rename `_silent` as `_changes`.
* Use `_changes` for both silent and immediate changes. This has the fortunate
property of removing the `changes` option to `change`.
* Do not default `options` to `{}` where not necessary.
* Most importantly, delete attrs from `_changes` unless `{silent: true}`.
* Use single branch for argument normalization.