Allow inference when the result has free variables.
Remove special case of subtype in tc-apply.
Add missing %s and corresponding unit tests.
Correctly extend tvars in the right place during inference.

Removes wrong extension of tvars in apply as well.
Make polydotted case more standard.
Handle inference of list dots under regular lists.
Make inference work with lists under dotted lists.
Infer in dotted lists when we can infer on the bound.
Support keywords with %.
Make infer-tests give better errors.
Correct subst/dots on list-dots and values-dots.
Add some more results to infer-tests.