Also, add the normal CUA bindings for Undo (^Z) and Redo (^Y),
and drop the M-X thinko.
With these more "usual" alternative bindings, ^X will now do a Cut
(putting the cut text into the cutbuffer) only when in the main menu
-- in the other places it did not put anything into the cutbuffer,
so it's better to have only the default ^K ("kill") for that.
Suspension is now accessible with ^E^Z, and the Speller with ^E^S.
This fixes https://savannah.gnu.org/bugs/?60766.
Bug existed since version 3.2, commit 33d67d5c,
since the more usual example bindings were introduced.
101dc4e805