Fix recently introduced test cases.
For datetime, gentoo didn't seem to mind the %e format for strftime.  So, we just excercise those instead making sure that we don't crash.
For test_os, two cases were incorrect.
diff --git a/Lib/test/test_datetime.py b/Lib/test/test_datetime.py
index 89fa5c8..24ec895 100644
--- a/Lib/test/test_datetime.py
+++ b/Lib/test/test_datetime.py
@@ -857,9 +857,18 @@
         self.assertEqual(t.strftime("'%z' '%Z'"), "'' ''")
 
         #make sure that invalid format specifiers are handled correctly
-        self.assertRaises(ValueError, t.strftime, "%e")
-        self.assertRaises(ValueError, t.strftime, "%")
-        self.assertRaises(ValueError, t.strftime, "%#")
+        #self.assertRaises(ValueError, t.strftime, "%e")
+        #self.assertRaises(ValueError, t.strftime, "%")
+        #self.assertRaises(ValueError, t.strftime, "%#")
+
+        #oh well, some systems just ignore those invalid ones.
+        #at least, excercise them to make sure that no crashes
+        #are generated
+        for f in ["%e", "%", "%#"]:
+            try:
+                t.strftime(f)
+            except ValueError:
+                pass
 
         #check that this standard extension works
         t.strftime("%f")