Don't pre-load facemenu

Don't pre-load facemenu

* lisp/facemenu.el (facemenu-add-face-function): Move to avoid a
compilation warning.
(facemenu-color-alist): Made obsolete.

* lisp/faces.el (read-color): Don't use it.

* lisp/loadup.el ("emacs-lisp/syntax"): Don't load facemenu.

* lisp/wid-edit.el (color): Don't use facemenu-color-alist.
(widget-color--choose-action): Require facemenu.
(widget-color-action): Ditto.

* lisp/progmodes/cperl-mode.el (facemenu): Require.

* lisp/textmodes/sgml-mode.el (facemenu): Require.