Make evaluator a separate file.
Clean up infer-tests.
Small style changes and removal of dead code.
Removal of define-go.
Remove unecessary lambda wrapper around test suites.
Make typechecking do the standard inits.
Make special env typecheck tests not run the code at module initialization.
Make all tests be marked by their defining module.
Making test suite files all have the same exported name.
Make test files have mains that run the test case defined in them.
Make expansion be marked in rackunit output.
Fixup broken tests and add missing gen-test-main.