Tag/Option Parsing in Prompts From File

add --ckpt-cache option for faster model switching

- Check the actually used `$python_cmd` and `$GIT` executables instead
  of the hardcoded ones
- Fix typo in comment

This is only necessary when you have to train,
and compiling model produces warning.

Fix XY-plot steps if highres fix is enabled

Raise an assertion error if no training images have been found.

Allow change set --index-url for pip.

And duplicate implementations are removed

attach an observer of gallery when generation in progress, if there was a image selected in gallery and gallery has only 1 image, auto re-select/open that image.

This matches behavior of prior to Gradio 3.4.1 version bump, is a quality of life feature many people enjoyed.

disabling history - i knew it was slow as fuck but i didn't realize it would also show galleries on launch

switching time reduced from ~1500ms to ~280ms

remove sigmoid and inverse sigmoid because they just did the same thing as weighed sum only with changed multiplier