(dabbrev-completion): Use mapcar, not mapc.

(dabbrev-completion): Use mapcar, not mapc.
Call dabbrev--reset-global-variables as the first thing.
(dabbrev-abbrev-char-regexp): Default value is nil again.
(dabbrev--find-all-expansions): Don't use push.
(dabbrev--search): Likewise.
(dabbrev-check-other-buffers):
Renamed from dabbrev-always-check-other-buffers.
(dabbrev-check-all-buffers): Renamed frm dabbrev-check-rest-of-buffers.
(dabbrev-expand): Now checks for marker.
(dabbrev--try-find): Now does a protected call to `widen'.
(dabbrev-always-check-other-buffers): Default now t.
(dabbrev--capitalize): Function deleted.
(dabbrev-completion): Use `capitalize'.