title: PopupMenu in wxPython with key press activated context menu items
body: <p>I have a GUI that creates a PopupMenu when I right click on a ListCtrl, and I'm able to select items from the PopupMenu with a (left) mouse click. In addition to this functionality, I'd like the context menu items to be able to be selected with specific key presses (e.g. "C" for "Clear", "A" for "Clear All").</p>
  
  <p>How can I do this?</p>
  
  <p>A snippet to show the idea-</p>
  
  <pre><code>self.listcontrol=wx.ListCtrl(self, wx.NewId(), style = wx.LC_LIST|wx.LC_SINGLE_SEL)
  self.listcontrol.Bind(wx.EVT_RIGHT_DOWN, self.OnFileRightDown)
  ...
  def OnFileRightDown(self,e):
    men=wx.Menu()
    cmi = wx.MenuItem(men, wx.NewId(), 'Clear All...')
    men.AppendItem(cmi)
    self.Bind(wx.EVT_MENU, self.OnClearAll,cmi)
    self.PopupMenu(men,e.GetPosition())
  </code></pre>
  
  <p>I'd like to be able to press "A" when the context menu pops up to execute the OnClearAll method defined elsewhere.</p>
  
  <p>I tried using an accelerator but couldn't get it to work.</p>
  
  <p>Thank you.</p>