commandline options for grid filetypes and max batch count

fix a bug in image resizing

added more info into readme

remove remote image as sample for img2img (it will now use a local image if you have one, none otherwise)

hide gradio progressbar for about 10% speed increase on my GPU; a commandline option to prevent hiding

added prompt verification: if it's too long, a warning is returned in the text field along with the part of prompt that has been truncated

refactoring: separated duplicate code from img2img and txt2img into a single function

proper seeds for img2img
a bit of refactoring

add feature demonstrations to readme

all images in batches now have proper seeds, not just the first one
added code to remove bad characters from filenames
added code to flag output which writes it to csv and saves images
renamed some fields in UI for clarity

added GFPGAN as an option for img2img
added GFPGAN as a tab
added autodetection for row counts for grids, enabled by default
removed Fixed Code sampling because no one can figure out what it does; maybe someone will be upset by removal and will tell me