* keyboard.c (READABLE_EVENTS_DO_TIMERS_NOW)

* keyboard.c (READABLE_EVENTS_DO_TIMERS_NOW)
(READABLE_EVENTS_FILTER_EVENTS)
(READABLE_EVENTS_IGNORE_SQUEEZABLES): New flags for readable_events.
get_filtered_input_pending, readable_filtered_events): Removed.
(tracking_off): Call readable_events and get_input_pending with
flag READABLE_EVENTS_DO_TIMERS_NOW.
(readable_events): Move code from old readable_filtered_events here,
but check new READABLE_EVENTS_* in argument flags instead of previous
two boolean arguments do_timers_now and filter_events.
If we are doing mouse tracking and the mouse moved, return only if
READABLE_EVENTS_IGNORE_SQUEEZABLES is not set in flags.
(swallow_events): Call get_input_pending with flag
READABLE_EVENTS_DO_TIMERS_NOW.
(get_input_pending): Move code from old   get_filtered_input_pending
here.  Replace boolean arguments do_timers_now, filter_events with
flags, and pass flags to readable_events.  Document new
READABLE_EVENTS_* flags.
(detect_input_pending_ignore_squeezables): New function.
(detect_input_pending_run_timers): Call get_input_pending with flag
READABLE_EVENTS_DO_TIMERS_NOW.
(Finput_pending_p): Call get_input_pending with flags
READABLE_EVENTS_DO_TIMERS_NOW and READABLE_EVENTS_FILTER_EVENTS.

* dispnew.c (update_window, update_frame_1): Replace calls to
detect_input_pending with detect_input_pending_ignore_squeezables
so that redisplay is not paused if the event queue contains only
mouse movements.

* lisp.h: Declare detect_input_pending_ignore_squeezables.