title: ToString() default CultureInfo
body: <p>I think I understand the CultureInfo usage.</p>
  
  <p>If I do simple :</p>
  
  <pre><code>const int a = 5;
  string b = a.ToString();
  </code></pre>
  
  <p>is it equal to :</p>
  
  <pre><code>const int a = 5;
  string b = a.ToString(CultureInfo.InvariantCulture);
  </code></pre>
  
  <p>In other words, does ToString() by default use <strong>InvariantCulture</strong> or <strong>CurrentCulture</strong> or neither ?</p>