Also:
- remove the restriction on the use of unquote in define-judgment-form
- allows limited use (I modes only) of judgment-forms in terms
- allows the use of define-relation with the search/unification
based random term generation
This adds the option to generate random terms that satisfy
judgment-forms and metafunctions.
Currently functionality does not include:
- patterns/terms using: ellipses, in-hole/hole and relatives, side-conditions, unquotes
- define-relation
- redex-check integration
