* Replaced all from ...py23 import * with explicit name imports, or removed completely when possible.
* Replaced tounicode() with tostr()
* Changed all BytesIO ans StringIO imports to from io import ..., replaced all UnicodeIO with StringIO.
* Replaced all unichr() with chr()
* Misc minor tweaks and fixes
This is useful to quickly add logging functionality to classes, and
to reduce boilerplate.
It adds a 'log' property to the class inheriting from it, which uses
logging.getLogger to get a logging.Logger (sigleton) object named after
<module>.<class> of self.
