Also:
* add a backtracking limit
* check for ground terms in both term and pat environments
when filling in generated patterns
* update tests to be consistent with the above
- handle parameters correctly when simplifying disequations
- rework term generation/disequation checking for parameters
- fix define-extended-metafunction w/r/t the above
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
