Add some "used with permission" mentions where external resources are referenced.

brettcannon · brettcannon · commit 07b954d1488c · 2016-01-15T09:53:51.000-08:00
Permission was validated prior to adding these markings.
diff --git a/Lib/datetime.py b/Lib/datetime.py
@@ -896,6 +896,7 @@ def isocalendar(self):
 
         ISO calendar algorithm taken from
         http://www.phys.uu.nl/~vgent/calendar/isocalendar.htm
+        (used with permission)
         """
         year = self._year
         week1monday = _isoweek1monday(year)
diff --git a/Lib/encodings/hp_roman8.py b/Lib/encodings/hp_roman8.py
@@ -5,6 +5,8 @@
     Original source: LaserJet IIP Printer User's Manual HP part no
     33471-90901, Hewlet-Packard, June 1989.
 
+    (Used with permission)
+
 """#"
 
 import codecs
diff --git a/Lib/unittest/__init__.py b/Lib/unittest/__init__.py
@@ -1,6 +1,6 @@
 """
 Python unit testing framework, based on Erich Gamma's JUnit and Kent Beck's
-Smalltalk testing framework.
+Smalltalk testing framework (used with permission).
 
 This module contains the core framework classes that form the basis of
 specific test cases and suites (TestCase, TestSuite etc.), and also a
