Issue #783: python3 compatible - fixed batched_dot

 - disabled fix_filter becaus theano uses "filter" as a method name;
 - fixed another instance of checking the error message;
 - fixed another instance affected by numpy isinstance(x, int) bug.
Issue #783: python3 compatible - fixed another use of reload.
Issue #783: python3 compatible - fixed another instance affected by numpy's isinstance(x, int) bug.