All language tests now pass. I expect there are other failures elsewhere, but I want to commit this before delving into them. My method for fixing the tests was to do as little as possible, keeping the tests as bad or as good as they were before I started. Mostly this was about changing references to the interpreter into references to the parser (since that is where the new* methods are now for ast containers) and then dealing with the new config object and its relationship to scopes.