title: wx.ListCtrl and column header tooltips
body: <p>I'm looking for a way to show tooltips whenever the user hovers the
  mouse on a column header of a wx.ListCtrl, is this possible?<br>
  I tried binding <code>wx.EVT_MOTION</code> but it looks like it works only for the
  list items, not the headers.. Am I doing something wrong?</p>
  
  <p>Thanks in advance!</p>
  
  <p>(wxPython 2.8.9.1 on Xubuntu 9.04) </p>