RFA, doc RFA: add symbol.type attribute

[Eli Zaretskii]

> Date: Thu, 11 Aug 2011 17:57:35 -0700 (PDT)
> From: dje@google.com (Doug Evans)
> 
> It seems an oversight to not export the type attribute of symbols,
> and I have a need of it.
> 
> Ok to check in?

With the comment below, the doco part os okay.

> +@defivar Symbol type
> +The type of the symbol or None if no type is recorded.

@code{None}, I think: it's a program symbol, right?

Thanks.