numpy.frompy have changed. I try to don't use it as this should be faster too.

complied with suggestion given by Fred.

This bug was found by the buildbot in debug mode.

They are all working except the outer one because outer doesn't turn into a GEMM
yet.

Add test on compute_test_value with __mul__. Fix test with this flag and make it more resistent to change in code.

This allow TensorVariable + SparseVariable to work correctly by calling after that __radd__ of the SparseVariable.

Also small update to documentation.