0.9.4.56:

0.9.4.56:
	Make VALIDATE-SUPERCLASS obey the rules.
	... ah, but we need an additional constraint for CLOS classes
		to behave: F-S-Cs must have FUNCTION in their CPL, while
		S-Cs mustn't.  Otherwise you end up with things which
		are functions but whose type-of isn't subtypep
		function, and similar disasters.
	... document this additional constraint.