GitLab

	* custom.el (custom-push-theme): Clarify docstring.  VALUE nil for
	reset means to remove setting from theme entirely.  Don't keep
	expanding theme-settings list; delete old entries if necessary.

	* cus-edit.el (custom-buffer-create-internal): Move "Erase
	customization" button one line up.
	(custom-themed): New face.
	(custom-magic-alist): New value, THEMED, for theme settings.
	(custom-variable-state-set): Check theme-value.
	(custom-variable-reset-standard, custom-face-reset-standard):
	Remove theme setting entirely.