title: Add string at beginning in wx.ListBox
body: <p>I am using wxPython 2.8 and in an application of mine I am using a wx.ListBox to add some strings when a specified event is fired. Each time the event is fired I need to add a string at top position of the wx.ListBox (the other strings will be positioned afterwards).</p>
  
  <p>If I have initially the wx.ListBox with following string:</p>
  
  <pre><code>World
  </code></pre>
  
  <p>and the next event stores in the listbox the string "Hello"; the result has to be:</p>
  
  <pre><code>Hello
  World
  </code></pre>
  
  <p>Is it possible ? I have not found any straightforward way to do it.</p>
  
  <p>thanks</p>