* Adds missing pop() methods to weakref.py
* Expands test suite to broaden coverage of objects with
a mapping interface.
Contributed by Sebastien Keim.
this can result in significantly smaller files. All classes as well as the
open function now accept an optional binary parameter, which defaults to
False for backward compatibility. Added a small test suite, updated the
libref documentation (including documenting the exported classes and fixing
a few other nits) and added a note about the change to Misc/NEWS.