Aider v0.50.0

• Infinite output for DeepSeek Coder, Mistral models in addition to Anthropic's models.
• New --deepseek switch to use DeepSeek Coder.
• DeepSeek Coder uses 8k token output.
• New --chat-mode <mode> switch to launch in ask/help/code modes.
• New /code <message> command request a code edit while in ask mode.
• Web scraper is more robust if page never idles.
• Improved token and cost reporting for infinite output.
• Improvements and bug fixes for /read only files.
• Switched from setup.py to pyproject.toml, by @branchvincent.
• Bug fix to persist files added during /ask.
• Bug fix for chat history size in /tokens.
• Aider wrote 66% of the code in this release.