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Extracting out validations to it's own module.
Extracting attribute code to the attributes module.

Simplifing Entity.
Upping version.

Methods from Minimapper::Entity::Attributes has moved to
Minimapper::Entity::Attributes::ClassMethods.
repository first word should be R
Changing to actual types instead of symbols.

This will make it simpler to break out the form handling from the entity.

It breaks the previous converter API a bit. But it's a trivial fix in most any app.