All tests in basics/ directory can now run and pass using 64-bit unix
port with only a 16k heap (./run-tests --heapsize 16k). Tests in this
directory should remain small so they can be used for ports with a
small heap.
In CPython IOError (and EnvironmentError) is deprecated and aliased to
OSError. All modules that used to raise IOError now raise OSError (or a
derived exception).
In Micro Python we never used IOError (except 1 place, incorrectly) and
so don't need to keep it.
See http://legacy.python.org/dev/peps/pep-3151/ for background.
Damien George