The __repr__ method of a NULL py_object does no longer raise an
exception.  Remove a stray '?' character from the exception text
when the value is retrieved of such an object.

Includes tests.
diff --git a/Misc/NEWS b/Misc/NEWS
index 587ed1e..712a997 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -64,6 +64,9 @@
 Library
 -------
 
+- The __repr__ method a NULL ctypes.py_object() does no longer raise
+  an exception.
+
 - uuid.UUID now has a bytes_le attribute. This returns the UUID in 
   little-endian byte order for Windows. In addition, uuid.py had some
   workarounds for clocks with low resolution, to stop the code yielding