title: Import of Open Sans Font in matplotlibrc Ubuntu fails
body: <p>I try to import the Font <a href="http://www.opensans.com" rel="noreferrer">Open Sans</a> over:</p>
  
  <pre><code>import matplotlib as mpl
  #update matplotlibrc
  mpl.rcParams['font.family'] = 'Open Sans'
  
  #testplot
  import matplotlib.pyplot as plt
  plt.plot(range(10))
  plt.title('Everything is crazy!!!', size=32)
  plt.show()
  </code></pre>
  
  <p>If I want to plot, the font can't be found by matplotlib, giving an error message like:</p>
  
  <pre><code>/usr/lib/pymodules/python2.7/matplotlib/font_manager.py:1236: UserWarning: findfont: Font family ['Open Sans'] not found. Falling back to Bitstream Vera Sans
        (prop.get_family(), self.defaultFamily[fontext]))
  
  /usr/lib/pymodules/python2.7/matplotlib/font_manager.py:1246: UserWarning: findfont: Could not match :family=Bitstream Vera Sans:style=normal:variant=normal:weight=light:stretch=normal:size=medium. Returning /usr/share/matplotlib/mpl-data/fonts/ttf/cmb10.ttf
        UserWarning)
  </code></pre>
  
  <p>The font is installed in Ubuntu and all the OpenSans-*.ttf Files are also copied to the matplotlib folder (/usr/share/matplotlib/mpl-data/fonts/ttf/ in Ubuntu).
  Any Idea how to use the font in the matplotlibrc?</p>