Always writing 'scalar Date' on the beginning of schema

[FelipeCoimbra]

Why does it have this behavior? Can we remove it?

[nevir]

This is to support uses of the JavaScript Date type—it needs to be special cased so that we're not walking all the built in fields of the Date interface.

Would definitely be interested in a patch that only emits that scalar Date line if you actually use a Date, though!