Better error message on Address validation fail

[Axxiss]

When an address validation fails, we're clueless about what went wrong. It could be really helpful to return a list of the missing/invalid params that caused the request to fail.

On Addresss doc there is a param list, stating on each field if its required or optional. IMHO those validations should be done inside the library.

[holgersindbaek]

+1

[att14]

Address validation rules are too complicated to do client side. I'm going to close this, but we are working on improving our verification system server side.