Don't return a value from map-over-command-menu-items (was trickling down to make lookup-keystroke-item return nonsense in the case where lookup failed).
Don't return a value from map-over-command-menu-items (was trickling down
to make lookup-keystroke-item return nonsense in the case where lookup
failed).

swflint/McCLIM,antifuchs/mcclim,slyrus/mcclim,onixie/mcclim,swflint/McCLIM,onixie/mcclim,slyrus/mcclim,antifuchs/mcclim,swflint/McCLIM,onixie/mcclim