[v3] container requirements cleanups

[Benjamin Kosnik]

> >   Is indeed untenable. If you ask me, let's leave basic_string
> > alone, not implementing for now any C++0x bits. If you want, I can
> > help reverting any bits which inadvertently got committed in the
> > past. 
> ... but that is not the case, neither possible for initializer_list,
> because the symbols are already exported. Thus, what I can say, the
> few cbegin / cend changes aren't particularly critical in my opinion,
> let's make sure however we don't further fiddle, until we are sure
> about the future of those facilities vs the C++0x requirements of a
> non-refcounted string.

It is my understanding that C++0x will require a non-refcounted string.
Or is this too a decision that may be reversed?

I'll start on the non-string extern template parts first.

-benjamin