Fixed another old-style exception
Add some missing copyright & licence statements
Implment StringIO import via Bio._py3k module

The goal here is to facilitate writing code which can be
run on both Python 2 and Python 3 without alteration via
2to3 (and fixing these imports currently needs 2to3).
Import StringIO via _py3k module in tests
Option to tag files as Python 2 only, or dual syntax Python 2 and 3
Update StringIO/BytesIO imports in run_tests.py

This is enough to run this file unmodified on both Python 2.6+
and Python 3.3
These files work unmodified on Python 3

Focussed on Tests/test_*.py which are quick to test, and
files which were particularly slow to convert via 2to3.
Tag the BioSQL test files needing 2to3 conversion
Can't use deprecated commands module under Python 3
Fix these to work on both Python 2 and 3 unchanged
Can't use deprecated commands module under Python 3
Fix these to work on both Python 2 and 3 unchanged
Tag these as needing work for dual 2 and 3 support
Default to not converting Tests/*.py with 2to3 (fails)