title: How I can create custom tool type for panels Header?
body: <p>I want to create tool type like maximize or minimize:</p>
  
  <pre><code>{
          type: 'my-type-name',
          tooltip: 'Make Toolbar Float',
          listeners: {
              click: function(panel , e , owner , eOpts){}
  }
  </code></pre>
  
  <p>To achive that I already created class in Tool.scss  as in theme-base</p>
  
  <pre><code>.#{$prefix}tool-tool-type-my-type-name{
      @include icon($tool-my-type-name-icon);
  }
  </code></pre>
  
  <p>But icon is private mixin and in Tool.scss not visible.
  After that I created own declaration of that class:</p>
  
  <pre><code> .#{$prefix}tool-tool-type-my-type-name{
      content: $fa-var-external-link;
      font-family: $font-icon-font-family;
      font-size: $tool-glyph-font-size;
      color: red;
      width:$tool-glyph-font-size;
      height:$tool-glyph-font-size;
  }
  </code></pre>
  
  <p>That didn't help.</p>