After a long list of discussion about the performance problem from using varargs and the reason that we can't find a great pair for it, it would be best to remove support for it for now. It will come back if we can find a good pair for it. For now, Bon Voyage, `#among?`.
There're a lot of places in Rails source code which make a lot of sense to switching to Object#in? or Object#either? instead of using .include?.
…neric AssociationScope class which is capable of building a scope for any association.
…he identity map is turned off
…on.options' with 'options'. Also add through_options and source_options methods for through associations.
…rectly accessing the instance variables
Conflicts: activerecord/lib/active_record/associations/association.rb activerecord/lib/active_record/fixtures.rb
…ch manages the association, and a CollectionProxy class which is *only* a proxy. Singular associations no longer have a proxy. See CHANGELOG for more.