Move memmon tooltip to hints.js

so it's with the other tooltips, and doesn't have to be re-sent from the server every time.

Also, allowed tooltips to be applied by matching a class name if all else fails.

added command line argument --autolaunch to open the webui URL in the system's default browser upon launch (implements #274)

replace existing image via paste or drop in inpaint mode (fixes #649)

add an option to disable lightbox modal

Close ImageViewer on escape

handle NoneType when subseed is not initialized

Polish seed UI options

Fix webui.sh not working

.gitignore - Exclude checkpoint files in models folder

Random button sets seed to -1, reuse copies the seed from the last
generated image.

change () to "" in .sh scripts because export AAA=(BBB CCC) sets AAA to BBB and does not export anything
whoever put that in .sh files - shame on you

Add some error handling for VRAM monitor

in case someone sets opts.memmon_poll_rate to 0 during generation

fix pasting of images from the clipboard in img2img (fixes #645)

altered progressbar to not rely on first progress request coming after the job has started; may help with broken progressbar some people say they have

split masking helper function from processing.py into new masking.py

fixed typos in processing.py