title: jQuery: Get double or multiple set rule(s)
body: <p>I want to get the rules of a css file that are double or multiple set
  so for example</p>
  
  <pre><code>#style1 {width:12px;}
  
  #style2 {width:12px;}
  
  .
  .
  .
  
  #style1 {width: 12px; height:12px;}
  </code></pre>
  
  <p>then jquery should give me "#style1 is defined double or multiple times"</p>
  
  <p>so how do i process css files in a website directly and css code and detect multiple set rules?</p>
  
  <p>it should work out of the box on every website as bookmarklet</p>