Add wrapper around layers.
Implement gradient.
Integration test for multilayer network.
Bugfix SSE.
Make DeepNetwork work on two spirals example.
Introduce temporary variables.
Add comparison of old and new implementation.
Major speed improvement.
Remove another speed bug.
Simplify loops.
Add more speed tests and fix speedbugs.

Costs for set/get parameters are a bit higher because the parameters are
distributed over memory but forward/backpropagation is faster.
Bugfix jacobian.
Remove magic number.
Solve MNIST with CNN.
Bugfix multiclass classification.
Add max-pooling layer.
Change standard deviation of initial weights.
Add rectified linear units.
Add mini-batch stochastic gradient descent with momentum and adaptive learning rates.
Do not log gains anymore.