[py3] Removed uses of sys.maxint under Python 3.

Also fixed #18706: improved exceptions raised by int_to_base36.

docs/releases/1.5.txt

@@ -244,6 +244,9 @@ Miscellaneous
 
 * GeoDjango dropped support for GDAL < 1.5
 
+* :func:`~django.utils.http.int_to_base36` properly raises a :exc:`TypeError`
+  instead of :exc:`ValueError` for non-integer inputs.
+
 Features deprecated in 1.5
 ==========================