title: Toggle a mixin in CesiumJS
body: <p>in order to have a better overview over the performance of a Cesium project, I would like to be able to toggle Cesium's inspector panel.
  Now I can add the Mixin with the following code</p>
  
  <pre><code>viewer.extend(Cesium.viewerCesiumInspectorMixin);
  </code></pre>
  
  <p>but how can I remove it from the Viewer? 
  Cannot seem to find a method in the viewer documentation. 
  Thanks!</p>