The following changes happened from the airblade branch:

• Remove the has_one relation reification. Seems weird to have belongs_to relations work substantially different than has_one relations. In our project we need all types of relation version control.
• Support the following case:

i = Item.create
v = i.versions.first
i.destroy
v.reify

In the upstream version v.reify will be nil. This a series of use cases not possible.

• On reification store the version object. This is so a reified object can look at the meta data that is stored in the version table.

• Fix a bug in reify when an attribute has been removed but there is still a setter method.