update ESRGAN architecture and model to support all ESRGAN models

Someone had 6000 images in their dataset, and it was shown as 0, which was confusing.
This will allow tracking real time dataset-average loss for registered objects.

added an option to always only show one image in previews
removed duplicate code

[Hypernetworks] Add a feature to use dropout / more activation functions

Implementation of CUDA device id selection (--device-id 0/1/2)