* Added a authorization rules browser.  See README for more information [sb]

* Added Model.using_access_control? to check if a model has model security activated [sb]

* Changed Authorization::ObligationScope#map_table_alias_for [Brian Langenfeld]
  * Fixed to prevent bad aliases from being produced.

* Changed Authorization::Attribute#validate? [Brian Langenfeld]
  * Encountering a nil value when evaluating an attribute now raises a NilAttributeValueError, instead of an AuthorizationError.  We leave it to the caller to decide what to do about it.

* Changed Authorization::Engine#permit! [Brian Langenfeld]
  * We now convert incoming privileges to symbols (e.g. 'read' is made equivalent to :read).  This ensures the privileges will match those defined in the authorization rules file.
  * The method now properly infers context when checking against an association (e.g. user.posts).  We do this by leveraging ActiveRecord builder method 'new' to instantiate a proper object we can work with.
  * When testing rules for positive results (via Authorization::Attribute#validate?), we now rescue NilAttributeValueError exceptions, simply causing the rule to return a negative result (instead of barfing).

* Changed Authorization::ObligationScope#rebuild_join_options! [Brian Langenfeld]
  * If we're dealing with multiple obligations we have to check (i.e. ones that result in OR'd conditions), we now use :include instead of :joins for our generated scope.  This does seem like a kludge, but until ActiveRecord scopes support unions (for checking obligations individually and consolidating the results), we don't have much choice.  Something to revisit later, for sure.

** RELEASE 0.2 (February 2, 2009) **

* added negative operators: is_not, not_in, does_not_contain [sb]

* changed user.roles to user.role_symbols to reduce interferance with associations [sb]

* Ruby 1.9 and Rails 2.3 compatibility [sb]

* if_permitted_to for has_permission_on blocks for DRYer auth rules [sb]

* ObligationScope rewrite of query rewriting [Brian Langenfeld]

* changed exception hierarchy to begin at StandardError [sb]

* :is_in operator [sb]

* added has_role? helper [sb]

* made plugin thread-safe [sb]

* added maintenance and test helpers [sb]

* changed default permission denied response to 403 Forbidden [sb]

* descriptions for titles and roles [sb]

* fixed for PostgreSQL [Mark Mansour]

* improved DSL syntax: allow for array of contexts in has_permission_on [sb]

** RELEASE 0.1 (August 22, 2008) **