Server large image files via a custom httpd on Colab

[JohnTigue]

This might be a way to get around the large images causing disconnects, assuming the problem is that the images are being transfered as base 64 data in jupyter internal comms:
https://colab.research.google.com/notebooks/snippets/advanced_outputs.ipynb#scrollTo=_7dYIo63EdgL

So, same algorithms to generate image files but just park them on the the Colab VM's FS. Then client directly loads image as if from a %%HTML magic or some JS.