Speed up image generation with improved image quality using Agent Attention.

• SD 1.5 Support
• SD XL Support (Requires Max Downsample > 1. If anybody knows the ideal settings to get this to work, please open an Issue!)

• The authors of the original paper for their method (https://arxiv.org/abs/2312.08874):

   @misc{han2023agent,
     title={Agent Attention: On the Integration of Softmax and Linear Attention}, 
     author={Dongchen Han and Tianzhu Ye and Yizeng Han and Zhuofan Xia and Shiji Song and Gao Huang},
     year={2023},
     eprint={2312.08874},
     archivePrefix={arXiv},
     primaryClass={cs.CV}
   }
  

• This extension uses code from the official AgentAttention repository: https://github.com/LeapLabTHU/Agent-Attention
• @udon-universe's extension templates (https://github.com/udon-universe/stable-diffusion-webui-extension-templates)