[AD] Exceptions, Stack, and Allegro

[Dustin Dettmer <dustin@xxxxxxxxxx>]

So whats going to happen with this?  Someone proposed
it be mentioned in the docs as a warning to C++
programers to simply not do it, but I think thats a
bit rash =\.

If the optimization is perticularly critical, maybe
some form of option when making / installing to add
stack support.  It would seem to me that the
optimization wouldnt do that much anyway, and
simplying removing it would fix the issue.