Merge pull request #7 from moreonion/palette-scroll

  var $list = $('ul.form-builder-fields', context);

  if ($list.length) {

    var $block = $list.parents('div.block:first').css('position', 'relative');

    var blockScrollStart = $block.offset().top;

    var $block = $list.parents('div.block:first').css('position', 'relative').css('top', 0 + 'px');

    function blockScroll() {

      // Do not move the palette while dragging a field.

        return;

      }

      var toolbarHeight = parseInt($('body.toolbar').css('padding-top'));

      var windowOffset = $(window).scrollTop() + (toolbarHeight ? toolbarHeight : 0);

      var blockHeight = $block.height();

      var formBuilderHeight = $('#form-builder').height();

      if (windowOffset - blockScrollStart > 0) {

      var blockScrollStart = $block.offset().top - parseInt($block.css('top'));

      var scrollTop = $(window).scrollTop();

      var windowHeight = $(window).height();

      // Calculate height of all elements made sticky by jquery.sticky.

      var stickyHeight = 0;

      $('.is-sticky').each(function(i, e) {

        var $e = $(e);

        // Only take elements into account that are near the top.

        if (scrollTop + windowHeight * 0.2 >= $e.offset().top) {

          stickyHeight = Math.max(stickyHeight, $e.offset().top + $e.height());

        }

      });

      var padding = 20;

      var windowOffset = scrollTop + stickyHeight + padding;

      // Do not scroll beyond the bottom of the editing area.

        var newTop = Math.min(windowOffset - blockScrollStart + 20, formBuilderHeight - blockHeight);

      var maxTop = $('#form-builder').height() - $block.height();

      var newTop = Math.min(windowOffset - blockScrollStart, maxTop);

      // Do not scroll up beyond the original position.

      newTop = Math.max(0, newTop);

      $block.animate({ top: (newTop + 'px') }, 'fast');

    }

      else {

        $block.animate({ top: '0px' }, 'fast');

      }

    }

    var timeout = false;

    function scrollTimeout() {