Use 2to3 in setup.py and mention that targetcli-fb is Python 3 compatible

Signed-off-by: Christophe Vu-Brugier <cvubrugier@yahoo.fr>
Merge pull request #28 from cvubrugier/master

Use 2to3 in setup.py and mention that targetcli-fb is Python 3 compatibl...