[wxPython] Thanks: wxTreeCtrl displays images now

Thanks to all of you out there!

Thanks Robin:

"Since wxImageLists are meant to be shared, the tree doesn't take over
ownership of the object like other things do in wxWindows. Because of this
you need to keep a reference to the image list so the C++ object isn't
destroyed when the Python one is."

Writing
  self.imageList=wx.wxImageList(16,16)

instead of
  imageList=wx.wxImageList(16,16)

solve the problem. Images now displayed either on Win32 either on Linux(+wxGTK+wxPython)

Zoltan Szalay
szz@philoslabs.com