Unify FRAME_window_system_DISPLAY_INFO macros between all ports.

Unify FRAME_window_system_DISPLAY_INFO macros between all ports.
All of them are replaced with FRAME_DISPLAY_INFO, defined in
each port to reference the port-specific window system data.
* msdos.h (FRAME_X_DISPLAY_INFO): Remove.
(FRAME_DISPLAY_INFO): Define.
* w32term.h (FRAME_W32_DISPLAY_INFO, FRAME_X_DISPLAY_INFO): Remove.
(FRAME_DISPLAY_INFO): Define.  Adjust users.
* xterm.h (FRAME_X_DISPLAY_INFO): Remove.
(FRAME_DISPLAY_INFO): Define.  Adjust users.
* frame.h (FRAME_RES_X, FRAME_RES_Y): Unify.
* font.c, frame.c, gtkutil.c, image.c, menu.c, msdos.c, nsfns.m:
* nsfont.m, nsterm.m, w32fns.c, w32font.c, w32menu.c, w32term.c:
* w32xfns.c, widget.c, xdisp.c, xfaces.c, xfns.c, xfont.c, xmenu.c:
* xselect.c, xterm.c: All related users changed.