Tune up repository layout

This is a tune-up of the cli_tools repository layout and brings cli_tools
to the same level as my more recent Python repositories.
Eliminate unittest2 and add support for Python 3.3

This eliminates the dependency on unittest2, which is not available
for Python 3, by replacing the only Python 2.6-incompatible assert.
It also adds testing against Python 3.3 and Python 3.4, and I have
confirmed that tests now run against Python 3.3.  The trove
classification has also been updated to reflect the Python 3.3 and
3.4 support.