README tweak.
document Form::Validate.
start prototyping on Form::Scalar, where a property can be nested (and define validations) but doesn't represent another "form model" but a simple object (e.g. a string, or an uploaded file object).
let populate! and deserialize! be the same.
make #populate! redundant. this saves us from calling #from_hash twice.
make Validate A HUNDRED TIMES simpler.
delete all the code in Populate.
cleanup F:Validate.
test.
working on Scalar form.