[Coco] Basic09 Level 3

[Wayne Campbell]

I did remember one item I would like to see added to Basic09. Aaron Wolfe
and I discussed it at length once, and we put one form of it in ccirc. It
is the ON SIGNAL signal trap, similar to the ON ERROR trap Basic09 already
has. With this, we can create event driven code in Basic09.

Another feature came to mind and left again faster than it came. When I
think of it again I will post.

Wayne