2.0.2
* Fixed deprecation warning under Rails 3.1 [Philip Arndt]
* Converted Test::Unit matchers to RSpec. [Uģis Ozols]
* Added inverse_of to associations to improve performance rendering trees. [Sergio Cambra]
* Added row locking and fixed some race conditions. [Markus J. Q. Roberts]

2.0.1
* Fixed a bug with move_to not using nested_set_scope [Andreas Sekine]

2.0.0.pre
* Expect Rails 3
* Changed how callbacks work. Returning false in a before_move action does not block save operations. Use a validation or exception in the callback if you need that.
* Switched to RSpec
* Remove use of Comparable