-- add print/save functionality.  Currently you can save by right
   clicking on the fig window, but you must have nothing in front of
   the window.  I suppose I need to first draw to a pixbuf.  I would
   also like to control the resolution.

-- fix text size calculations using pango layouts
 
-- add a font selection dialog for the axis text

-- enable vertical rendering for ylabels

-- enable anti aliasing for fonts

-- enable fancy text labels (eg, greek letters, math symbols,
   superscripts) ala TeX or unicode

-- add a color selection dialog for the background, lines, and text

-- allow interactive control of the plot from the python shell after
   it has been launched using the cookbook thread recipe.

-- write a user guide

-- allow more intelligent choice of tick labels and locs when panning and
   zooming.

-- figure out why the positioning of dialog boxes based on position
   and size of main window and dialog window doesn't work exactly as
   expected.  For example, the width of the dialog box is being
   reported as being much smaller than it is.  Is window pixels the
   unit being returned by for gtk.Dialogs.get_size?  Also, this isn't
   working cross platform.  According to the docs this is better
   handled using size hints -- but I don't know how to use them, yet.


-- vlines and hlines disappear on in some instance due to improper
   clipping

-- One the errorbar demo the hlines do not always appear symmetric
   about the x values.  Is there an tranformation or rounding problem
   occurring somewhere?

