Initial python3 changes

Mostly just updating libraries, removing string encoding/decoding,
fixing some edge cases. No new functionality was added in this
commit.

lib/pkg_resources/tests/data/my-test-package-source/setup.py

@@ -0,0 +1,6 @@
+import setuptools
+setuptools.setup(
+    name="my-test-package",
+    version="1.0",
+    zip_safe=True,
+)