Feature: allow multiple hidden layers

[AlexCMueller]

I have a feeling that the neural network will be better at picking out suffixes and such if there are several hidden layers, increasing the accuracy.

[AlexCMueller]

Error (ria-tsu) on htwins pointed out that having ReLU cells in the next to last layer should help even more than adding hidden layers, because it encourages categarization.

[hanss314]

This should be a project.