(x-create-frame-with-faces): Set background-mode

(x-create-frame-with-faces): Set background-mode
and display-type frame parameters.
(x-frob-font-slant, x-frob-font-weight):
Replace the adstyle field with *, if we can find it.
(set-face-background): Use face-color-supported-p.
(face-color-gray-p): New function.
(face-default-stipple): New variable.
(set-face-background): Use face-default-stipple for all grays.
(set-face-stipple): Change arg name.
(face-color-supported-p): Use face-color-gray-p.