Add _tensor_variable.cumprod/cumsum() interface in the theano/tensor/var.py files, in
the _tensor_py_operators class
Update var.py
change imports locations
Update var.py
add nnet
Update var.py
Update var.py
Update var.py
fix some imports
Merge pull request #1762 from nicholas-leonard/master

Add subgraph_grad
Mark opt as inplace
Make tests pass in fast_compile.
Merge pull request #1771 from nouiz/fast_compile

[BUG] in fast compile related to inplace opt.
bugfix, for a case that don't happen right now.

The preallocated output size for make_vector should ALWAYS be the good
shape right now as it only depend on the ndim and that is constant in
the graph and we only give preallocated output of the same node.

This fix will be useful in the futur if we make other type of
preallocated output that could be of the wrong size.
Merge pull request #1773 from nouiz/make_vector_bug

bugfix, for a case that don't happen right now.
Move the access to strides outside of the loop.
small code cleanup
Refactor code to reuse it later.
Use vectorized version of exp in the Softmax op.
Same speed up for SoftmaxWithBias