Document log rotation settings in 2.5.x

In the Troubleshooting/Logs and Logging section in the 2.5.x Admin Guide, instructions are given on how to change the logging levels and location by editing the static_config file.

What's not covered is changing the rotation size (error_logger_mf_maxbytes) and number of rotations (error_logger_mf_maxfiles) from the defaults (10MB and 20 respectively).

There is a serious gotcha here as these values are encoded in the .siz files in the log directory itself, and if you change them in static_config then Couchbase Server will not start unless you completely empty the log directory.