Fixing up for rails3
Reworking for Rails 3.

* Removed jeweler
* Switched to RSpec
* Various cleanups
* Work in progress ;)
Updated readme
Finished fixing specs after Rails 3 refactoring.
Add support for saving without validation for rebuild

Add support for saving without validation for rebuild
Added "parent_column_name => nil" condition to root method.  Previous version assumed that the DB would return the root node first, otherwise root would not return a root node.
Stripping whitespace at the request of @lenary.
Removed outdated links in Readme.
Added support for counter_cache columns
Updated gemspec for 2.0.0.pre
Prep for 2.0.0
use define_model_callbacks instead of define_callbacks

ActiveSupport::Callbacks.define_callbacks doesn't define the class
macros to create callbacks (anymore?). This means that in 2.0.0,
before_move, after_move, and around_move are missing.

ActiveModel::Callbacks.define_model_callbacks handles defining the
macros, and as a bonus adds the `:terminator` option itself.
Fix up usage of deprecated code (class_inheritable attributes).
Fixed bug in move_to with scopes. (via Andreas Sekine)
Bumped version to 2.0.1
Note 2.0.1 in the changelog
add inverse_of to associations to improve performance rendereing trees
    Cherry pick of row locking logic from vamosa's fork plus extention to set_default_left_and_right case (ANS issue #70)
Merge pull request #75 from parndt/patch-1

Fix up usage of deprecated code (class_inheritable attributes).
Merge pull request #80 from scambra/master

add inverse_of to associations