docs patch: dicts and sets

[Alan Isaac]

This discussion ended abruptly, and I'd like to see it reach a
conclusion.  I will attempt to synthesize Bill and Carsten's
proposals.

There are two proposed patches.  The first is to
http://docs.python.org/lib/typesmapping.html
where it is proposed for footnote (3) to state:

    Keys and values are listed in an arbitrary order.  This order is
    indeterminate and generally depends on factors outside the scope
    of the containing program.  However, if items(), keys(), values(),
    iteritems(), iterkeys(), and itervalues() are called with no
    intervening modifications to the dictionary, the lists will
    directly correspond.

The second is for http://docs.python.org/lib/types-set.html
where the proposal is to append a new sentence to the 2nd paragraph:

    Iteration over a set returns elements in an indeterminate
    order,which generally depends on factors outside the scope of the
    containing program.

Alan Isaac