Fix possible V8 vulnerability using `prepareStackTrace`

Benvie pointed out that allowing the stack tracing utility functions allows a user to break out of the inner context and gain access to the full node.js process. While this will still be limited by the timeout, this is still a huge security hole. This is my first attempt to patch that hole.

I tried a lot of little things myself but I don't know if this truly fixes the issue. To feel comfortable, I would like @Benvie to hammer on it with his expertise.