Improving logging format

1. Make the request format match whatever the standard style is (e.g. https://en.wikipedia.org/wiki/Common_Log_Format).
2. Log error messages to a different file (per https://httpd.apache.org/docs/1.3/logs.html).
3. Gate debug messages behind `-development` or maybe a new flag.

The issue names no files or tests. Start by locating the request, error, and debug logging entry points, then compare the request format and error separation with the cited Common Log Format and Apache logging documentation. Done means the three logging behaviors are implemented and the development-only debug control is defined.

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