Metadata fixes

Fix remaining references to PSF license, change maintainer info.
Removed most occurances of __author__, since it felt redundant
with the copyright notice (credit) and package metadata
(developer contact).

Also fixed references to Python 2.3 (it's not even tested anymore)
and changed calls from python3 to just python (let the system decide).
diff --git a/updatezinfo.py b/updatezinfo.py
index ae8b772..415b8c3 100755
--- a/updatezinfo.py
+++ b/updatezinfo.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python3
+#!/usr/bin/python
 from dateutil.zoneinfo import rebuild
 import shutil
 import sys