* [attribute]_before_typecast should become [attribute]_before_type_cast (note the extra _)
* Change validates_exclusion_of :within option to :in
* Change validates_inclusion_of :within option to :in
* descendants now returns all descendants use direct_descendants for just children
* Switch validate_on_create and validate_on_update use validate :on => :create syntax
* Added #update_attribute
* belongs_to and one associations now return a true nil instead of a proxy to nil, so you must now call .build_thing instead of thing.build.
* Plugins should now extend ActiveSupport::Concern
0.7.6 => 0.8
* Proxy#owner has been removed in favor of Proxy#proxy_owner
* @new instance variable renamed to @_new (you shouldn't be using this anyway)
* Removed undefining of object_id in proxies and equal? method in Equality. This means checking equal? for a proxy and a regular document will always be false even if proxy refers to same document. Check Proxy#target instead. (ie: root.equal?(item.root.target))
* find no longer takes options as a last argument. It only works with id, multiple ids, array of ids.
* MongoMapper::MongoMapperError is now MongoMapper::Error
* metaclass, meta_eval, meta_def, class_def removed as they were not being used