FEATURE Entity fieldset's id have child id appended to it.
+ stops them being ambiguous
BillingProfile now prepares the models used to create it and the property asks for it to prepare itself.
Avoided calling back when creating BillingProfile. Preferred explicit call against the more magical
after_initialize. Couldn't get the reject_if working and settled on marking unwanted objects for
distruction during before validation - if I didn't use a callback I would have to have to have know if
it was going to save before hand!
Heavy testing suite for BillingProfile - many new techniques.
Contact delete and moved into Profile and BillingProfile - review it when it's matured.
Entity and Address have empty? operators
billing_profile.use_profile is not bool operator that decides if we save billingprofile information or not