Fix bitwidth check

Fixes issue #23

model.py

@@ -16,7 +16,7 @@ def has_hidden(layer):
 def matrixify(vector, n):
     # Cast n to int32 if necessary to prevent error on 32 bit systems
     return T.repeat(T.shape_padleft(vector),
-                    n if (theano.gof.local_bitwidth() == 64) else T.cast(n,'int32'),
+                    n if (theano.configdefaults.local_bitwidth() == 64) else T.cast(n,'int32'),
                     axis=0)
 
 def initial_state(layer, dimensions = None):