Add Liver (+ Lesion) Segmentation

[kmader]

There is a pretrained model for liver segmentation at https://github.com/IBBM/Cascaded-FCN but no Docker, so packaging it to work with DeepInfer would take some work

[mpslxz]

@kmader I appreciate your feedback. That sounds very interesting. Please feel free to launch the docker, if you are interested. However, if you like to do so, you need to confirm the license with the authors.