(Fx_file_dialog): Pass a filter to GetOpenFileName.

(Fx_file_dialog): Pass a filter to GetOpenFileName.

Sync with xfns.c:
(x_laplace_read_row, x_laplace_write_row): Removed.
(postprocess_image): New function.
(lookup_image): Call it for all image types except PostScript.
(x_kill_gs_process): Call postprocess_image.
(tiff_error_handler, tiff_warning_handler): New functions.
(tiff_load): Install them as handlers.
(x_kill_gs_process): Recognize if someone has cleared the image
cache under us.
(valid_image_p): Protect better against invalid image
specifications.  Previous code could signal an error.
(Fx_hide_tip, Fshow_tip): Doc fix.
(Fv_max_tooltip_size): New variable.
(syns_of_xfns): DEFVAR_LISP it.
(Fx_show_tip): Add parameter TEXT.  Set the tip frame's root
window buffer to *tip* right after creating the frame. Set frame's
window_width.  Use a maximum tooltip size specified by
Vx_max_tooltip_size, if that has valid contents.
(compute_tip_xy): Add parameters WIDTH and HEIGHT.
Make sure the tooltip is completely visible.
(x_create_tip_frame): Set tooltip buffer's truncate-lines to nil.
(Fx_create_frame): Adjust the frame's height for presence
of the tool bar before calling x_figure_window_size.
(x_set_tool_bar_lines): Clear the tool bar window's current matrix
when the window gets smaller.
(x_set_foreground_color): Set frame's cursor_pixel.
(x_set_foreground_color, x_set_background_color): Cleaned up.
(x_set_font): Handle case of x_new_fontset returning the same name
as before, although there was a change in fontsets.