Iterator isEqual semantics

[<eric@son-of-blob>]

I was just talking with Dean about how Iterator::isEqual should behave.  The
main issue that arose is whether or not Iterator::isEqual should be an ordered
or an unordered comparison of the elements.  The current opinion is that as
Iterators themselves do not imply an order, the normal isEqual on Iterators
should be unordered, but that if you have an Iterator that you know to be
an ordered subclass, an ordered comparison would be available.  The final
conclusion we reached is that we wanted to bounce it off of you.
	-e-