Added setitem for CudaNdarray based on suggestions from Fred. Can only assign another CudaNdarray, and no support for broadcast in assignment, for the moment.

fix syntax error of tensor.ARange.infer_shape found by Justin Brayer and fix behavior error found while making test for that case.

Added test for this. The new graph are ugly... 12 ops with dimshuffles and rebroardcast...

 Optimization removed due to a bug noticed in the tutorials .. I will be trying to fix this as soon as possible.

This allow all other optimization to work correctly. This allow the insertion of gemm into gpu code in the deep learning tutorial of the mlp to have a speed up of 3x.

updated test to check for this.

The timming is done on maggie, so it could differ on other computer.