keyboard.c, keymap.c: Use bool for booleans.

keyboard.c, keymap.c: Use bool for booleans.

* dispnew.c (sit_for): Distinguish between 3-way display_option
and boolean do_display.
* keyboard.c (single_kboard, this_command_key_count_reset)
(waiting_for_input, echoing, immediate_quit, input_pending)
(interrupt_input, interrupts_deferred, pop_kboard)
(temporarily_switch_to_single_kboard, ignore_mouse_drag_p)
(command_loop_1, adjust_point_for_property)
(safe_run_hooks_error, input_polling_used, read_char):
(help_char_p, readable_events, kbd_buffer_events_waiting)
(kbd_buffer_get_event, timer_check_2, make_lispy_event)
(lucid_event_type_list_p, get_input_pending):
(gobble_input, menu_separator_name_p, menu_bar_item)
(parse_menu_item, parse_tool_bar_item, read_char_x_menu_prompt)
(read_char_minibuf_menu_prompt, access_keymap_keyremap)
(keyremap_step, test_undefined, read_key_sequence)
(detect_input_pending, detect_input_pending_ignore_squeezables)
(detect_input_pending_run_timers, requeued_events_pending_p)
(quit_throw_to_read_char, Fset_input_interrupt_mode):
* keymap.c (get_keymap, keymap_parent, keymap_memberp)
(access_keymap_1, access_keymap, map_keymap, get_keyelt)
(Fdefine_key, Flookup_key, struct accessible_keymaps_data)
(accessible_keymaps_1, Fkey_description, push_key_description):
(shadow_lookup, struct where_is_internal_data)
(where_is_internal, Fwhere_is_internal, where_is_internal_1)
(Fdescribe_buffer_bindings, describe_map_tree, struct describe_map_elt)
(describe_map, describe_vector):
* menu.c (single_menu_item):
* nsmenu.m (ns_update_menubar):
* process.c (wait_reading_process_output):
* search.c (scan_buffer, scan_newline):
Use bool for boolean.
* keyboard.c (timers_run, swallow_events)
(detect_input_pending_run_timers):
* process.c (wait_reading_process_output):
Use unsigned for counter where wraparound-on-overflow is desired,
since unsigned is guaranteed to have that behavior and signed is not.
(read_char): Use ptrdiff_t for string length.
(get_input_pending): Remove first argument, since it was always
the same pointer-to-int (now pointer-to-boolean) &input_pending,
and behave as if it had that value.  Return new value of
input_pending.  All callers changed.
* keyboard.h (struct kboard): Use unsigned : 1 for boolean member
immediate_echo.  Use ptrdiff_t for echo_after_prompt, since it's
a string length.
* keymap.c (push_key_description): Omit last arg, which was always 1.
All callers changed.