title: QString::number() 'f' format without trailing zeros
body: <p>I want to convert number to <code>QString</code> with 3 significant digits.</p>
  
  <pre><code>QString::number(myNumber,'f',3);
  </code></pre>
  
  <p>does the job but remains trailing zeros. How to use it without them.</p>
  
  <p>Also I've tried <code>'g'</code> and which shouldn't remain those zeros:</p>
  
  <pre><code>QString::number(myNumber,'g',3);
  </code></pre>
  
  <p>but  for example 472.76 is converted to 473. That surprised me. Why is it so with <code>'g'</code> option?</p>
  
  <p><strong>However I am interested in <code>'f'</code> format. So the main question is how to do it with <code>'f'</code> without trailing zeros?</strong></p>
  
  <p>Input -> Desired output</p>
  
  <p>472.76 -> 472.76</p>
  
  <p>0.0766861 -> 0.077</p>
  
  <p>180.00001 -> 180</p>