(help_echo_object, help_echo_pos): New variables.

(help_echo_object, help_echo_pos): New variables.
(note_mode_line_highlight): Store additional information about the
help-echo in help_echo_object and help_echo_pos.  Check both
`local-map' and `keymap' properties for changing the cursor
(note_mouse_highlight): Store additional information about the
help-echo in help_echo_object and help_echo_pos.
(note_tool_bar_highlight): Set help_echo_object to nil and
help_echo_pos to -1.
(w32_read_socket): Use gen_help_event instead of filling
input_events manually.
(syms_of_w32term): Staticpro help_echo_object.
(x_update_window_end): Add parameter MOUSE_FACE_OVERWRITTEN_P. If
set, arrange for a mouse-highlight redisplay in
XTframe_up_to_date.
(x_clear_mouse_face): New function.
(w32_redisplay_interface): Add pointer to x_clear_mouse_face.
(x_update_window_begin): No need to turn off the mouse
highlight here.
(show_mouse_face): Set the mouse_face_p flag of glyph rows
depending on whether they contain glyphs highlighted in
mouse-face.
(x_fill_stretch_glyph_string): Consume runs of stretch
glyphs instead of a single one.
(BUILD_STRETCH_GLYPH_STRING): Call x_fill_stretch_glyph_string
with new argument list.
(x_set_glyph_string_gc): Make sure the face's GC is valid.
(x_append_glyph, x_append_composite_glyph)
(x_produce_image_glyph, x_append_stretch_glyph): Accomodate to
changes in struct glyph starting 1999-12-27. See comments for
xterm.c on 2000-07-05.