title: IE HTML1114 Error with custom CLeditor button
body: <p>I am using CLeditor, Fineuploader, and Bootstrap to create a custom button that pops up a more advanced file upload Modal. But everytime I launch the modal I get an error and I have no idea how to fix it. Basically the whole browser freezes. </p>
  
  <pre><code>HTML1114: Codepage unicode from (UNICODE byte order mark) overrides conflicting codepage windows-1252 from (11) 
  </code></pre>
  
  <p>I found what was going wrong this warning still displays but it carries on normally.</p>
  
  <p>So CLeditor has a terrible design where it runs the command on custom buttons on click rather than waiting for the <code>buttonClick</code> callback to be run this created a situation where IE was calling <code>getRange(editor).pasteHTML(value)</code> with a value of <code>undefined</code> to mitigate it I just added my button name to the big if else if in the <code>buttonClick</code> event handler </p>
  
  <pre><code>// Image uploader
  else if (buttonName === "uploadImage") {
    return;
  }
  
  // All other buttons AVOID THIS NONSENSE FOR CUSTOM BUTTONS!!!
  else if (!execCommand(editor, data.command, data.value, data.useCSS, buttonDiv)) {
     return false;
  }
  </code></pre>