generic code cleanup toward py3k compatibility
removed unittest2 dependency
removed anything related to unicode
converted all **u""** style unicode string definitions to normal strings
removed all __eq__ methods in a try to pass tests under python 3
Stalker is now fully python 3 compatible
fixed str/unicode python 2 incompatibility
fixed a couple of issues about str/bytes/unicode/python2/python3 in Link and Version classes
fixed str/unicode/bytes/python2/python3 incompatibility in Link.py
updated changelog and setup.py to include Python 3 in python classifiers