Issue #783: python3 compatible - fixed another instance of sorting a list of types.
Issue #783: python3 compatible - fixed pickle test. (Use six.BytesIO.)
Issue #783: python3 compatible - fixed name conflicts.

 - iter is a builtin
 - io is a standard lib module in 3.x.
ssue #783: python3 compatible - fixed error message checking.
Issue #783: python3 compatible - refactored any() into a loop to make python 3 happy.

In python 3, list comprehention variables do not leak in the outside scope.  In this
case the loop is actually cleaner.