Don't require timer; use autoloaded functions from Emacs or XEmacs,
depending on variant.
Do not use defsubst anywhere. Replace with defuns.
(type-break-warning-message-mode): Variable deleted.
(type-break-query-mode): New variable and function.
(type-break-mode): Mention in docstring.
(type-break-run-at-time): New function.
All callers of run-at-time changed.
(type-break-cancel-function-timers): New function.
All callers of cancel-function-timers changed.
(type-break-check-post-command-hook): New function.
(type-break-mode, type-break-schedule, type-break-alarm,
type-break-time-warning-alarm): Call it.
(type-break-mode-line-countdown-or-break): New function.
(type-break): Call it.
(type-break-time-warning-schedule): Put type-break-time-warning
on type-break-post-command-hook.
(type-break-check): Call type-break-mode-line-countdown-or-break.
(type-break-noninteractive-query): New function.
(type-break-force-mode-line-update): New function.