detect 64-bit systems using maxsize not maxint

setup.py

@@ -696,7 +696,7 @@ class PyBuildExt(build_ext):
         exts.append( Extension('audioop', ['audioop.c']) )
 
         # Disabled on 64-bit platforms
-        if sys.maxint != 9223372036854775807L:
+        if sys.maxsize != 9223372036854775807L:
             # Operations on images
             exts.append( Extension('imageop', ['imageop.c']) )
         else: