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.

Added first shot at normal distribution in mrg_rng, with tests adapted from the ones James used for uniform

MakeVector.perform - optimization. modifying to skip asarray() when output space is already allocated.