Added comment about int_division config flag.

theano/configdefaults.py

@@ -26,6 +26,11 @@ AddConfigVar('cast_policy',
                ),
         )
 
+# python 2.* define int / int to return int and int // int to return int.
+# python 3* define int / int to return float and int // int to return int.
+# numpy 1.6.1 do as the python 2.*. I think we should not change it faster
+# then numpy. When we will do the transition, we should create an int_warn
+# and floatX_warn option.
 AddConfigVar('int_division',
         "What to do when one computes x / y, where both x and y are of "
         "integer types",