an_id	IN:	AN interface identifier returned by ANstart
	annot_type	IN:	Type of the annotation
	obj_tag	IN:	Tag of the object
	obj_ref	IN:	Reference number of the object

	Purpose	Returns the number of annotations of a given type attached to an object.
	Return value	Returns the number of annotations or FAIL (or -1) otherwise.
	Description	ANnumann returns the total number of annotations that are of type annot_type and that are attached to the object identified by its tag, obj_tag, and its reference number, obj_ref.
		Since this routine is implemented only to obtain the total number of data annotations and not file annotations, the valid values of annot_type are AN_DATA_LABEL (or 0) and AN_DATA_DESC (or 1). To obtain the total number of file annotations or all data annotations, use ANfileinfo.

	FORTRAN	integer function afnumann(an_id, annot_type, obj_tag, obj_ref)
		integer an_id, obj_tag, obj_ref, annot_type