iterators in feisty meow suck

[Fred T. Hamster]

the iterator implementations are all fubar;
they are not nice.
they are all kind of different.

either fix up the iterator to use a coherent base class and
calling approach or drop it.
maybe stl iterator could be used instead?

we should certainly at least be _able_ to provide STL operators
for our classes, so people can treat them the way they're used
to, by now.