Run all validations when in primary code path.

This commit adds the explicit javascript-based checking of the `repeat`,
`length`, `range`, and `required` properties to the usual-case code path.
The `default` property was already being checked in this way, and remains
untouched.

Previously, these functions were intended for use only in validating properties
returned from script directives. It makes sense to run them everywhere, though,
if only for unit testing and QA purposes -- so they're now enabled.