Validators implicitly require value #8
Description
IValidationFunctions has many functions that implicitly add a "required" constraint from their type.
For example: Float is string Formlet -> float Formlet, but should be string Formlet -> float option Formlet since the user might not submit a value.
There should also be a function 'a option Formlet -> 'a Formlet validating a required value.
In short, I need to decouple requiredness validation,