Initial fun for Array iterator.

We are missing yet:

1. The special key+value return value (which I haven't seen in action anywhere yet, but still documented in the spec)
2. Plugging it into the Array @@iterator call.

I expected to send this request yesterday, but was too tired and forgot ;(

I got sick of writing the OP(*,Get)() form instead of Get(), so I actually added a Get() method (should be in ejs-object.c).