New in 0.22:
* Requires gtk+extra-0.99.17.
* GtkPlotData.set_gradient() and get_gradient() now get/return the number
  of sublevels as an additional parameter.
* GtkPlotData.set_points() accepts the tuple returned by get_points() as
  input.
* Removed GtkCheckItem.

New in 0.21:
* The bindings are now a package, ie. gtkextra/__init__.py is used
  instead of gtkextra.py.  Please remove the old bindings before
  installing the new version.

New in 0.20:
* The bindings are now built and installed with the Python
  Distribution Utilities.  Read the document "Installing Python
  Modules" that comes with Python for more information about the
  Distutils.
* GtkCheckItem is now an alias for the standard GtkCheckButton.

New in 0.19:
* Added the GtkPlotData subclass GtkPlotPixmap.  See testpixmap.py for
  more information.
* Added the GtkCharSelection dialog.
* Added the attribute GtkFontCombo.psfont.

New in 0.18:
* Requires gtk+extra-0.99.16.
* Added GtkPlot.set_background_pixmap(), set_transparent(),
  is_transparent().
* Removed GtkPlot.plot_set_flags(), plot_unset_flags() and
  PLOT_TRANSPARENT.  Use GtkPlot.set_transparent() instead.
* GtkFileList.open_dir() now returns a boolean value indicating
  success or failure.
* Added GtkIconFileSelection.show_tree().  Note: Use show() instead of
  show_all() to manage a GtkIconFileSelection dialog.  If the dialog
  is managed with show_all() the tree widget, that is now disabled by
  default, will be shown and the GtkExtra code won't work correctly.
* Applied a patch from Joe Van Andel that fixes a Numerical Python
  problem.

New in 0.17:
* Updated GtkPlot.put_text() and GtkPlotCanvas.put_text().  The angle
  must now be put after the font height in the argument list.  In
  previous versions the angle had to be put before the font name.
* Renamed all *_get_visible() functions to *_visible().  The old
  Pythons methods are still available though.
* GtkPlot.get_pixel() and GtkPlot3D.get_pixel() now return floating
  point values instead of integers.
* Added GtkPlot.clip_data().  If the method's argument is TRUE the
  plot data is clipped to fit the frame.
* GtkPlot.draw_line() now gets floating point values instead of
  integers.
* Updated GtkPlot.axis_set_attributes(), axis_get_attributes(),
  axis_set_ticks_width(), y0line_set_attributes(),
  x0line_set_attributes, major_vgrid_set_attributes(),
  minor_vgrid_set_attributes(), major_hgrid_set_attributes() and
  minor_hgrid_set_attributes().  The width is now a floating point
  value.
* Updated GtkPlot.axis_title_set_attributes().  The method now gets
  the transparency and the justification as additional arguments.
* Renamed GtkPlot.axis_labels_set_attributes() to
  axis_set_labels_attributes().  The method now gets the transparency
  and the justification as additional arguments.
* Renamed GtkPlot.axis_labels_set_numbers() to
  axis_set_labels_numbers().
* Removed GtkPlot.axis_set_tick_labels().  Custom labels are now set
  with the signal "tick_label". This signal is not supported by the
  Python bindings.
* Updated GtkPlot3D.corner_set_attributes(), corner_get_attributes(),
  frame_set_attributes(), frame_get_attributes() and
  axis_set_ticks_width().  The width is now a floating point value.