fix NEWS header
1.1.11: will be tagged as "sbcl-1.1.11"
Remove an unused variable, *unwind-to-frame-function*.

It isn't used for about three years now.
Remove debug-deinit, unused.

Its body consist of
;; Nothing to do right now. Once there was, maybe once there
;; will be again.

Once there is something to do, it can easily be put back.