Added support for RNNs, which are implemented by calling a network multiple times with the respective previous output.
Initialization and invocation of networks was extended to make use of RNN states.
Support for Beamsearch was added, currently only works with batches of size 1. Patch to follow.
SoftmaxCrossEntropyIgnoreIndices loss and BLEU eval_metric were introduced. "use_teacher_forcing" and "save_attention_image" flags can be used in training.
Added possibility to extract attention layer from network and save it as image.
Added backend implementation of new layers from CNNArch.
Added tests and datasets (or scripts to generate datasets too large for git) for recurrent networks. Updated dependencies.