 

 
returns the relative position of point
p to the oriented sphere defined by the points in A = tuple [first,last) The order of the points in $$A is important,
since it determines the orientation of the implicitly constructed
sphere. If the points in $$A are positively oriented, the positive
side is the bounded interior of the sphere. Precondition: A contains $$d+1 points in $$dspace. Requirement: The value type of ForwardIterator is Kernel::Point_d. 