Log Message:
Update ruby-acts-as-versioned package to 0.6.0.

Depends on Ruby on Rails 3 and here is CHANGELOG although it would not
be complete one.

* (16 Jun 2008) Backwards Compatibility is overrated (big updates for rails 2.1)

  * Use ActiveRecord 2.1's dirty attribute checking instead [Asa Calow]
  * Remove last traces of #non_versioned_fields
  * Remove AR::Base.find_version and AR::Base.find_versions, rely on AR \ 
association proxies and named_scope
  * Remove #versions_count, rely on AR association counter caching.
  * Remove #versioned_attributes, basically the same as AR::Base.versioned_columns

* (5 Oct 2006) Allow customization of #versions association options [Dan Peterson]

*0.5.1*

* (8 Aug 2006) Versioned models now belong to the unversioned model.  \ 
@article_version.article.class => Article [Aslak Hellesoy]

*0.5* # do versions even matter for plugins?

* (21 Apr 2006) Added without_locking and without_revision methods.

  Foo.without_revision do
    @foo.update_attributes ...
  end

*0.4*

* (28 March 2006) Rename non_versioned_fields to non_versioned_columns (old one \ 
is kept for compatibility).
* (28 March 2006) Made explicit documentation note that string column names are \ 
required for non_versioned_columns.

*0.3.1*

* (7 Jan 2006) explicitly set :foreign_key option for the versioned model's \ 
belongs_to assocation for STI [Caged]
* (7 Jan 2006) added tests to prove has_many :through joins work

*0.3*

* (2 Jan 2006) added ability to share a mixin with versioned class
* (2 Jan 2006) changed the dynamic version model to MyModel::Version

*0.2.4*

* (27 Nov 2005) added note about possible destructive behavior of if_changed? \ 
[Michael Schuerig]