issues with pyparsing 1.5.7 and python 2.7

You can reproduce this error with 

```
In [13]: ax = gca()

In [14]: plot(range(1, 15))
Out[14]: [<matplotlib.lines.Line2D at 0x9735890>]

In [15]: ax.set_yscale('log')

In [16]: draw()
```

It works properly if you update to 2.0.1.

1.5.7 is the system version that is in the current ubuntu beta.

```
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-7-46f60fa8c8fd> in <module>()
----> 1 exec(compile(open('/tmp/ipython-4094kLU.py').read(), '/tmp/ipython-4094kLU.py', 'exec')) # PYTHON-MODE

/tmp/ipython-4094kLU.py in <module>()

/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/pyplot.pyc in draw()
    556 
    557     """
--> 558     get_current_fig_manager().canvas.draw()
    559 
    560 

/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/backends/backend_qt4agg.pyc in draw(self)
    159         # causes problems with code that uses the result of the
    160         # draw() to update plot elements.
--> 161         FigureCanvasAgg.draw(self)
    162         self.update()
    163 

/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/backends/backend_agg.pyc in draw(self)
    449 
    450         try:
--> 451             self.figure.draw(self.renderer)
    452         finally:
    453             RendererAgg.lock.release()

/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/artist.pyc in draw_wrapper(artist, renderer, *args, **kwargs)
     52     def draw_wrapper(artist, renderer, *args, **kwargs):
     53         before(artist, renderer)
---> 54         draw(artist, renderer, *args, **kwargs)
     55         after(artist, renderer)
     56 

/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/figure.pyc in draw(self, renderer)
    964         if self.get_tight_layout() and self.axes:
    965             try:
--> 966                 self.tight_layout(renderer, **self._tight_parameters)
    967             except ValueError:
    968                 pass

/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/figure.pyc in tight_layout(self, renderer, pad, h_pad, w_pad, rect)
   1603                                          renderer,
   1604                                          pad=pad, h_pad=h_pad, w_pad=w_pad,
-> 1605                                          rect=rect)
   1606 
   1607         self.subplots_adjust(**kwargs)

/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/tight_layout.pyc in get_tight_layout_figure(fig, axes_list, subplotspec_list, renderer, pad, h_pad, w_pad, rect)
    350                                      subplot_list=subplot_list,
    351                                      ax_bbox_list=ax_bbox_list,
--> 352                                      pad=pad, h_pad=h_pad, w_pad=w_pad)
    353 
    354     if rect is not None:

/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/tight_layout.pyc in auto_adjust_subplotpars(fig, renderer, nrows_ncols, num1num2_list, subplot_list, ax_bbox_list, pad, h_pad, w_pad, rect)
    127         #ax_bbox = union([ax.get_position(original=True) for ax in subplots])
    128 
--> 129         tight_bbox_raw = union([ax.get_tightbbox(renderer) for ax in subplots])
    130         tight_bbox = TransformedBbox(tight_bbox_raw,
    131                                      fig.transFigure.inverted())

/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/axes/_base.pyc in get_tightbbox(self, renderer, call_axes_locator)
   3184             bb.append(self._right_title.get_window_extent(renderer))
   3185 
-> 3186         bb_xaxis = self.xaxis.get_tightbbox(renderer)
   3187         if bb_xaxis:
   3188             bb.append(bb_xaxis)

/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/axis.pyc in get_tightbbox(self, renderer)
   1058         ticks_to_draw = self._update_ticks(renderer)
   1059         ticklabelBoxes, ticklabelBoxes2 = self._get_tick_bboxes(ticks_to_draw,
-> 1060                                                                 renderer)
   1061 
   1062         self._update_label_position(ticklabelBoxes, ticklabelBoxes2)

/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/axis.pyc in _get_tick_bboxes(self, ticks, renderer)
   1041         for tick in ticks:
   1042             if tick.label1On and tick.label1.get_visible():
-> 1043                 extent = tick.label1.get_window_extent(renderer)
   1044                 ticklabelBoxes.append(extent)
   1045             if tick.label2On and tick.label2.get_visible():

/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/text.pyc in get_window_extent(self, renderer, dpi)
    751             raise RuntimeError('Cannot get window extent w/o renderer')
    752 
--> 753         bbox, info, descent = self._get_layout(self._renderer)
    754         x, y = self.get_position()
    755         x, y = self.get_transform().transform_point((x, y))

/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/text.pyc in _get_layout(self, renderer)
    327                 w, h, d = get_text_width_height_descent(clean_line,
    328                                                         self._fontproperties,
--> 329                                                         ismath=ismath)
    330             else:
    331                 w, h, d = 0, 0, 0

/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/backends/backend_agg.pyc in get_text_width_height_descent(self, s, prop, ismath)
    208         if ismath:
    209             ox, oy, width, height, descent, fonts, used_characters = \
--> 210                 self.mathtext_parser.parse(s, self.dpi, prop)
    211             return width, height, descent
    212 

/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/mathtext.pyc in parse(self, s, dpi, prop)
   3007         # with each request.
   3008         if self._parser is None:
-> 3009             self.__class__._parser = Parser()
   3010 
   3011         box = self._parser.parse(s, font_output, fontsize, dpi)

/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/mathtext.pyc in __init__(self)
   2191         space         <<= oneOf(self._space_widths.keys())
   2192         customspace   <<= (Suppress(Literal(r'\hspace'))
-> 2193                           - ((lbrace + float_literal + rbrace)
   2194                             | Error(r"Expected \hspace{n}")))
   2195 

TypeError: unsupported operand type(s) for +: 'NoneType' and 'NoneType'

In [8]: Traceback (most recent call last):
  File "/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/backends/backend_qt4.py", line 416, in idle_draw
    self.draw()
  File "/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/backends/backend_qt4agg.py", line 161, in draw
    FigureCanvasAgg.draw(self)
  File "/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/backends/backend_agg.py", line 451, in draw
    self.figure.draw(self.renderer)
  File "/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/artist.py", line 54, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)
  File "/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/figure.py", line 966, in draw
    self.tight_layout(renderer, **self._tight_parameters)
  File "/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/figure.py", line 1605, in tight_layout
    rect=rect)
  File "/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/tight_layout.py", line 352, in get_tight_layout_figure
    pad=pad, h_pad=h_pad, w_pad=w_pad)
  File "/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/tight_layout.py", line 129, in auto_adjust_subplotpars
    tight_bbox_raw = union([ax.get_tightbbox(renderer) for ax in subplots])
  File "/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/axes/_base.py", line 3186, in get_tightbbox
    bb_xaxis = self.xaxis.get_tightbbox(renderer)
  File "/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/axis.py", line 1060, in get_tightbbox
    renderer)
  File "/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/axis.py", line 1043, in _get_tick_bboxes
    extent = tick.label1.get_window_extent(renderer)
  File "/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/text.py", line 753, in get_window_extent
    bbox, info, descent = self._get_layout(self._renderer)
  File "/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/text.py", line 329, in _get_layout
    ismath=ismath)
  File "/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/backends/backend_agg.py", line 210, in get_text_width_height_descent
    self.mathtext_parser.parse(s, self.dpi, prop)
  File "/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/mathtext.py", line 3009, in parse
    self.__class__._parser = Parser()
  File "/home/tcaswell/local_installs/lib/python2.7/site-packages/matplotlib-1.4.x-py2.7-linux-x86_64.egg/matplotlib/mathtext.py", line 2193, in __init__
    - ((lbrace + float_literal + rbrace)
TypeError: unsupported operand type(s) for +: 'NoneType' and 'NoneType'
```