== Welcome

This is an experiment.

Goal: A hierarchy of classes by inheritance whose attribute definitions can be
defined by the user (vs. the coder).

Given you have the base class named Product - it may have a name (and a price,
    but we don't care for this, right?).  When you inherit Product with
"Clothes" by creating a new Classification and add an AttributeDefinition
(:size, :integer), then you can instanciate this class and rails uses its STI
technique.

But instead of creating a column for every (possible) attribute, the user can
add more an more to it.