Fix broadcast pattern of dnn conv op.
hack to lower the number of compilation on the GPU.
remove import not used
Generate less GpuContiguous implementation
crash fix to the new tests that will be in the next commit.

Make subtensor.make_node infer more broadcastable. This remove crash from local_subtensor_merge that was loosing broadcastable dimensions.
Test dnn conv outputs broadcastable information.
lower the number of GPU op compiled
[CRASH] we where returning a python int while this was reused in Elemwise.perform that expect ndarray.
remove warning from code check tool about hiding name
Merge pull request #2298 from nouiz/convdnn_broadcast

Fix broadcast pattern of dnn conv op.