Fix UnicodeDecodeError from #114. Replace definitions of _unicode and

_string. Add six as a dependeny. Fix clonedigger script.

tox.ini

@@ -8,6 +8,7 @@ deps =
      pyyaml
      pytest
      mock
+     ipdb
      pytest-cov
 commands = py.test -v --cov pylast --cov-report term-missing {posargs}
 
@@ -27,4 +28,4 @@ commands =
     pyflakes tests
     pep8 pylast
     pep8 tests
-    clonedigger pylast -o /dev/stdout | grep -E "Clones detected\|lines are duplicates"
+    ./clonedigger.sh