[PATCH] Add support for trace and error output streams in Common Lisp

[akater]

This patch can't be merged right away: I need to sort out the exact
SLIME version where the feature will be introduced. Some doc update is
needed, too.

According to orgmode.org, I can link to a public repository and the
branch.
Repository: https://gitlab.com/akater/org-mode
Branch: ob-lisp-traces-and-errors

The patch can be reviewed in web browser:
https://gitlab.com/akater/org-mode/-/commit/e7dbc0b8

URI for all commits, just in case:
https://gitlab.com/akater/org-mode/-/commits/ob-lisp-traces-and-errors

This is a follow-up to the message
https://lists.gnu.org/archive/html/emacs-orgmode/2020-04/msg00137.html
Unfortunately, I can't reply to the message directly at the moment.

I mentioned compatibility issue for users who wouldn't update SLIME and
Org simultaneously; this patch resolves the issue for users with new Org
and old SLIME.