support EMA weights in processing (????)

Otherwise, we may override it with one of the next two path (. or ..) if it is present there, and then the local paths of other modules (taming transformers, codeformers, etc.) wont be found in sd_path/../.

Fix https://github.com/AUTOMATIC1111/stable-diffusion-webui/issues/1085

I had to check the code to work out what splitting was 🤷🏿

add --force-enable-xformers option and also add messages to console regarding cross attention optimizations

xformers attention