title: dont append but overwrite log file of logger
body: <p>I use logger in my application and direct the output to a file like this: </p>
  
  <pre><code>Logger.new("nemobuild.log")
  </code></pre>
  
  <p>My logger appends to this logfile once its created. </p>
  
  <p><strong>What i want it to do is to clear the logfile on each program start.</strong> </p>
  
  <p>In the examples is a description for creating a new logfile: </p>
  
  <pre><code>file = File.open('foo.log', File::WRONLY | File::APPEND | File::CREAT)
  </code></pre>
  
  <p><em>What <code>File::</code> params would i have to use to get the desired behaivior?</em></p>