Adding more information to exceptions

[Andrej Mitrovic]

On 1/30/13, Jonathan M Davis <jmdavisProg at gmx.com> wrote:
>> "The next parameter is used internally and should be always be null when
>> passed by user code."
>
> Really? That's a weird note. I don't see any reason for it to not be used by
> user code. I wonder why that note is there.

It should probably be changed, TDPL shows how .next is used in
user-code as well.