title: Fixed height when panel is scrollable?
body: <p>the following code shows a definition of one of my views I'm using in my current app, that means this view is easily created and added to the <em>Ext.Viewport</em> when it should be displayed.</p>
  
  <p>Its structure is quite easy: there's a toolbar with a panel underneath, which can contain any other components like buttons, panels etc.</p>
  
  <p>But: my problem is, that since I added the config <strong>scrollable: true</strong> to the panel (as you can see below), I also have to set a fixed height for that panel (300 in this case). If I don't set a height, all components within the panel aren't displayed at all.</p>
  
  <p>The even worse problem is, that I don't know <strong>what</strong> height I should set here, because my app should of course work on different devices with different screen-sizes (iPhone/iPad/...).</p>
  
  <p>So what I want to achieve is that the panel under the toolbar uses the fully available height and - in case its contents are "higher" than its own height - it should be scrollable. Hope you can help me with that :-)</p>
  
  <pre><code>Ext.define('PV.view.Menu', {
      extend: 'Ext.Panel',
  
      xtype: 'menu',
  
      config: {
          items: [
              {
                  xtype: 'toolbar',
                  title: 'My Menu'
              },
              {
                  xtype: 'panel',
                  scrollable: true,
                  height: 300,
                  items: [
                      {
                          xtype: 'button',
                          text: 'Navigate to view 1 &gt;',
                          action: 'nav-to-view1'
                      },
                      {
                          xtype: 'button',
                          text: 'Navigate to view 2 &gt;',
                          action: 'nav-to-view2'
                      },
                      {
                          html: 'A lot of text&lt;br /&gt;A lot of text&lt;br /&gt;A lot of text&lt;br /&gt;A lot of text&lt;br /&gt;A lot of text'
                      }
                  ]
              }
          ]
      }
  });
  </code></pre>