title: ScrollMagic: Stick element to bottom of sticky/fixed element
body: <p>I try to use "setPin" method of scrollmagic to make an element sticky at a certain moment. 
  I made a screencast to show you my problem: <a href="https://www.dropbox.com/s/7r1xu1gdgm22is8/stick.mov?dl=0" rel="nofollow noreferrer">https://www.dropbox.com/s/7r1xu1gdgm22is8/stick.mov?dl=0</a>
  As you can see i am already manipulating the header section with scrollmagic (resizing the logo). When the blue bar reaches the sticked header section, i want it to be sticked too so the blue bar is always visible. Hope it is clear what i mean?! :)
  by default scrollmagics setpin method triggers when element reaches the viewport center. but i want the trigger when element "touches" the bottom border of my sticked header.
  This is my code so far:</p>
  
  <pre><code>jQuery(document).ready(function($){
      var controller = new ScrollMagic.Controller();
      var introTl = new TimelineLite();
      introTl.to(logoimg, 1, {width: 100, autoRound:false});
      var introScene = new ScrollMagic.Scene({duration: 200}).setTween(introTl).addTo(controller);
      var scene2 = new ScrollMagic.Scene({
        triggerElement: "#actionbar"
      })
      .setPin("#actionbar")
      .addTo(controller);
  });
  </code></pre>