title: log4net - Remove old files rolling by date
body: <p>INTENT: </p>
  
  <p>a) I want my logs to be rolled by date in following file format yyyy-MM-dd.txt. </p>
  
  <p>b) Additionally to this I want to remove old files which are out of maxSizeRollBackups range.</p>
  
  <blockquote>
  <pre><code>CAUTION A maximum number of backup files when rolling on date/time 
    boundaries is not supported. [RollingFileAppender spec][1]
  </code></pre>
  </blockquote>
  
  <p>SOLUTION</p>
  
  <p>for a) is enough to do the configuration</p>
  
  <pre><code>&lt;appender name="FileAppender" type="log4net.Appender.RollingFileAppender"&gt;
    &lt;file value="logs\" /&gt;
    &lt;appendToFile value="true" /&gt;
    &lt;rollingStyle value="Date" /&gt;
    &lt;maxSizeRollBackups value="30" /&gt;
    &lt;datePattern value="yyyy-MM-dd'.txt'" /&gt;
    &lt;staticLogFileName value="false" /&gt;
    &lt;layout type="log4net.Layout.XmlLayoutSchemaLog4j"/&gt;
    &lt;lockingModel type="log4net.Appender.FileAppender+MinimalLock" /&gt;
  &lt;/appender&gt;
  </code></pre>
  
  <p>for b)
  Is the inheritance from RollingFileAppender + delete stuff the only way to achieve this ?</p>