* support some torchvision datasets
* improvements to TFDS wrapper for subsplit handling (fix#942), shuffle seed
* add class-map support to train (fix#957)
* Add parser/dataset factory methods for more flexible dataset & parser creation
* Add dataset parser that wraps TFDS image classification datasets
* Tweak num_classes handling bug for 21k models
* Add initial deit models so they can be benchmarked in next csv results runs