Default log rotation is bad

[mithrandi]

The default logging settings for axiomatic.log (as well as Mantissa's http.log, see twisted/mantissa#63) are unbounded, and use ordinal rotation; this means that rotation cost scales linearly with the number of historic log files, and this number is unbounded, resulting in your process eventually blocking for minutes at a time renaming tens of thousands of files every time a new log file is started. This is not ideal, and also not obvious to debug.