NAME
	function_exists - find a function in an object

SYNOPSIS
	varargs string function_exists(string function, object obj)


DESCRIPTION
	Find the named function, which must be callable with call_other(),
	in an object.  If the function is found, the name of the inherited
	object that defines it is returned; otherwise, zero is returned.
	The second argument is optional, and defaults to this_object().

	Config.h must define MUDOS_FUNCTION_EXISTS for this function to
	exist.

SEE ALSO
	kfun/call_other, kfun/function_object, efun/previous_function