title: Symfony console ProgressBar component is not displayed in composer scripts
body: <p>Using the <a href="http://symfony.com/doc/current/components/console/helpers/progressbar.html" rel="nofollow">ProgressBar component</a> in a command called by a <a href="https://getcomposer.org/doc/articles/scripts.md" rel="nofollow">composer script</a> has no effect as the ProgressBar output is not shown.</p>
  
  <p>Why is this? Is there a way to enforce its rendering?</p>
  
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  <p>Update: Now (since upgrade to symfony 2.6) it is shown, but the console refresh doesn't work correctly and for each update is adds a new line...</p>