Run the transformer after running the native v0.11.2+ tests.

The native tests don't depend on the conversion from ES6 to ES5, so we
might as well make sure we get the native test results regardless of
whether the transformer succeeded.
Add a test of NewExpressions that causes the transformer to abort.

As reported by @radford in #60.
Implement an explodeExpression case for NewExpression nodes.

Closes #60.