CNN-Mimick and DyNet 2.0

[yuvalpinter]

This branch adds two major components:

1. Code upgraded to support DyNet 2.0. One caveat is that loading models have to be while knowing the internal parameters of the model (see DyNet documentation). There's an old_load function that supports the old format, but not plug-and-play.
2. A CNN version of Mimick! This version currently supports only one layer of convolution. The architecture is conv -> max-pooling -> FC -> tanh -> FC. There are no saved models available. Results with new models will hopefully be published in due time (no spoilers for now).

Also, the code is now more readable and less scattered in general.