RAM optimization round 2

Attempt to resolve NaN issue with unstable VAEs in fp32 mk2

Fix img2img background color for transparent images option not being used

Make image viewer actually fit the whole page

fix issues with api model-refresh and vae-refresh

More hash filename patterns

Make results column sticky

fix model override logic

api support get image from url

Gallery: Set preview to `True`, allow custom height

Improve interrupt speed

fix typo `txt2txt` -> `txt2img`

Get python print statements to show up in docker logs

update xformers to 0.0.21 and some fixes

refactor: Update ui.js

do not need extra logic to unload refine model

fix Return empty list if extensions dir not exist 

auto add data-dir to gradio-allowed-path