Don't include stdlib.h or string.h. Include atimer.h.

Don't include stdlib.h or string.h.  Include atimer.h.
(gray_width, gray_height): Remove defines.
(gray_bits, gray_bitmap_width, gray_bitmap_height)
(gray_bitmap_bits): Remove variables.
(lispy_function_keys): Remove extern.
(free_frame_menubar): Add extern.
(x_window_to_frame): Remove function.
(unwind_create_tip_frame): Add declaration.
(x_set_name_internal): New function.
(x_set_name, x_set_title): Use it.
(Fx_create_frame, Fx_display_grayscale_p, Fx_display_pixel_width)
(Fx_display_pixel_height, Fx_display_planes)
(Fx_display_color_cells, Fx_server_max_request_size)
(Fx_server_vendor, Fx_server_version, Fx_display_screens)
(Fx_display_mm_height, Fx_display_mm_width)
(Fx_display_backing_store, Fx_display_visual_class)
(Fx_display_save_under, Fx_synchronize, Fx_show_tip): Doc fixes.