Dedicated syntax highlighting server for cgit. Use a simple HTTP server to highlight source for cgit. Improves performance compared to invoking python on every request. Requirements: - Python 3.5.3+ (for aiohttp and asyncio.get_running_loop) - aiohttp - pygments Usage: 1. Run `make install`. 2. Set /usr/local/lib/cgit/syntax-highlighting-server.py to run at boot. This can be done by `systemctl enable syntax-highlighting` on systemd machines. 3. Set your cgit source filter to syntax-highlighting-client.sh. Security: aiohttp is not designed with security in mind. Slow clients can easily cause excessive memory usage by sending very large highlighting requests, or by opening a large number of connections and abandoning them. Therefore, cgit-syntax-highlighting SHOULD NOT be exposed to the public Internet. Suggestions are accepted for more lightweight asynchronous Python HTTP server libraries.