* lisp/play/gamegrid.el (gamegrid-setup-default-font): Clamp
font size at eight.

* lisp/play/gamegrid.el (gamegrid-calculate-glyph-size): Use
`frame-monitor-attributes' to get the frame attributes directly
instead of iterating over `display-monitor-attributes-list'.

* lisp/play/gamegrid.el (gamegrid-make-glyph): Declare
image-scaling-factor as special before dynamically binding it, for
the sake of --without-x builds which do not preload lisp/image.el.

* lisp/faces.el (face-background-pixmap)
(set-face-background-pixmap): Make XEmacs compat aliases obsolete in
favor of 'face-stipple' and 'set-face-stipple'.  Update callers.

* lisp/emacs-lisp/gv.el (face-background-pixmap): Make XEmacs
alias obsolete as a generalized variable.
(face-stipple): New generalized variable.
* doc/misc/cl.texi (Setf Extensions): Refer to above new generalized
variable instead of the obsolete one.

* lisp/play/gamegrid.el (gamegrid-calculate-glyph-size): Use the
monitor where the current frame is displayed rather than the primary
monitor.

* lisp/play/gamegrid.el (gamegrid-glyph-height-mm): Decrease
height a bit (since it wasn't really that height).
(gamegrid-calculate-glyph-size): Change calculation to work on
both X and pgtk (bug#49937).
(gamegrid-make-glyph): Inhibit image scaling.

* lisp/play/gamegrid.el (gamegrid-init-buffer):
* lisp/mwheel.el (mouse-wheel-scroll-amount):
(mouse-wheel-text-scale):
* lisp/faces.el (set-face-attribute):
* lisp/face-remap.el (text-scale-mode-step):
(text-scale-increase):
(text-scale-adjust):
* lisp/cus-face.el (custom-face-attributes):
* doc/emacs/frames.texi (Mouse Commands):
* doc/emacs/display.texi (Text Scale): Talk about font sized instead
of "face height" (bug#46853).

* lisp/play/gamegrid.el (gamegrid-make-glyph): Warn on using obsolete
XEmacs style glyph.  (This is currently unused in the Emacs tree.)
(gamegrid-make-image-from-vector): Make obsolete.