title: Why drupal adds version number to js path?
body: <p>Why the drupal adds the version number (like ?v=XXX) into the .js libraries?
  For example:</p>
  
  <pre><code>&lt;script type="text/javascript" src="http://localhost/misc/jquery.js?v=1.4.4"&gt;&lt;/script&gt;
  </code></pre>
  
  <p>And what means strange text at the end of path to .css files (after the '?' sign):</p>
  
  <pre><code>@import url("http://localhost/modules/system/system.menus.css?lrrru5");
  </code></pre>