Somewhere in help usage, we use both "message" and "msg", "command"
and "cmd", "key id" and "key-id". This patch makes all help text from
parseopt use the first form. Clearer and 3 fewer strings for
translators.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>