Introduce Pure GTK3 port

Introduce Pure GTK3 port

* src/xsettings.h:

* src/xsettings.c:
(dpyinfo_valid, store_tool_bar_style_changed)
(XSETTINGS_FONT_NAME, get_prop_window, read_settings)
(apply_xft_settings, read_and_apply_settings)
(xft_settings_event, init_xsettings, xsettings_initialize):

* src/xfaces.c:
(x_create_gc, x_free_gc):

* src/xdisp.c (redisplay_tool_bar, redisplay_internal)
(draw_glyphs_debug, draw_glyphs, mouse_face_from_buffer_pos)
(note_mouse_highlight):

* src/terminal.c (Fterminal_live_p):

* src/termhooks.h (enum output_method, GCALIGNED_STRUCT)
(TERMINAL_FONT_CACHE):

* src/process.c (wait_reading_process_output):

* src/pgtkterm.h:

* src/pgtkterm.c:

* src/pgtkselect.h:

* src/pgtkselect.c:

* src/pgtkgui.h:

* src/pgtkfns.c:

* src/image.c:
(XGetPixel, XPutPixel, image_create_bitmap_from_data)
(image_create_bitmap_from_file, free_bitmap_record)
(image_destroy_x_image, gui_put_x_image, image_get_x_image)
(Create_Pixmap_From_Bitmap_Data, xbm_load_image, )
(xpm_load_image, lookup_rgb_color, image_disable_image)
(image_build_heuristic_mask, imagemagick_load_image):

* src/gtkutil.h:

* src/gtkutil.c (PGTK_TRACE, xg_set_screen, xg_display_open)
(xg_display_close, xg_create_default_cursor)
(xg_get_pixbuf_from_pix_and_mask, xg_check_special_colors)
(qttip_cb, hierarchy_ch_cb, xg_prepare_tooltip, )
(xg_show_tooltip, xg_hide_tooltip, xg_frame_resized)
(xg_frame_set_char_size, xg_height_or_width_changed)
(xg_set_widget_bg, style_changed_cb, xg_create_frame_widgets)
(xg_free_frame_widgets, x_wm_set_size_hint, xg_frame_restack)
(xg_mark_data, xg_update_frame_menubar, free_frame_menubar)
(xg_update_submenu, xg_finish_scroll_bar_creation)
(xg_update_scrollbar_pos, xg_update_horizontal_scrollbar_pos)
(xg_set_toolkit_scroll_bar_thumb, xg_event_is_for_scrollbar)
(draw_page, xg_pack_tool_bar, xg_create_tool_bar)
(xg_update_tool_bar_sizes, update_frame_tool_bar)
(free_frame_tool_bar, xg_change_toolbar_position):

* src/ftcrfont.c:
(ftcrfont_draw):

* src/fringe.c:
(init_fringe_bitmap):

* src/frame.h (GCALIGNED_STRUCT, FRAME_WINDOW_P):

* src/frame.c (Fframep):

* src/font.h:

* src/font.c (syms_of_font):

* src/emacsgtkfixed.c:
(emacs_fixed_get_preferred_width)
(emacs_fixed_get_preferred_height, XSetWMSizeHints):

* src/emacs.c (main):

* src/dispnew.c (init_display_interactive):

* src/dispextern.h:

* src/alloc.c:
(garbage_collect):

* src/Makefile.in (PGTK_OBJ, PGTK_LIBS, base_obj, LIBES):

* src/.gdbinit:

* lisp/url/url-privacy.el (url-setup-privacy-info):

* lisp/term/pgtk-win.el (featurep):

* lisp/startup.el (command-line, fancy-splash-frame):

* lisp/net/eww.el (eww-form-submit, eww-form-file)
(eww-form-checkbox, eww-form-select):

* lisp/mwheel.el (mouse-wheel-down-event, mouse-wheel-up-event):

* lisp/loadup.el (featurep):

* lisp/international/mule-cmds.el (set-coding-system-map):

* lisp/frame.el (pgtk-frame-geometry, frame-geometry)
(w32-frame-edges, frame-edges)
(pgtk-mouse-absolute-pixel-position)
(mouse-absolute-pixel-position)
(pgtk-set-mouse-absolute-pixel-position)
(pgtk-frame-list-z-order, frame-list-z-order)
(pgtk-frame-restack, frame-restack, display-mouse-p)
(display-graphic-p, display-symbol-keys-p, )
(display-pixel-height, display-mm-height, display-mm-width)
(display-backing-store, display-save-under, display-color-cells)
(display-planes, display-visual-class)
(pgtk-display-monitor-attributes-list)
(display-monitor-attributes-list):

* lisp/faces.el (face-spec-set-match-display, tool-bar):

* lisp/cus-edit.el (custom-button, custom-button-mouse)
(custom-button-pressed, custom-display):

* configure.ac (AUTO_DEPEND, XARGS_LIMIT, XWIDGETS_OBJ):