Handle types from types module

[hoodmane]

The types module has a bunch of things like ModuleType: ModuleType.__module__ is
"builtins" and ModuleType.__name__ is "module", but it should be referenced as types.ModuleType.

To deal with these, I made a dict of values exported from types to the export name. If an annotation
is in this dict, we use "types" as the module and the reported name as the name.

I also made a couple of nonfunctional changes:

1. I think _is_newtype is more readable as a separate method so I factored it out.
2. test_parse_annotation displays more useful error messages if we assert two tuples are equal than if we make three sequential assertions -- this way we can see if more than one are wrong.