title: Matplotlib legend fontsize
body: <p>Am I using the fontsize argument incorrectly in the following code? 
  According to the <a href="http://matplotlib.org/api/pyplot_api.html#matplotlib.pyplot.legend" rel="noreferrer">documentation</a>, this should be a valid keyword argument.</p>
  
  <pre><code>import pylab
  pylab.plot(range(5), label='test')
  pylab.legend(fontsize='small') 
  pylab.show()
  </code></pre>
  
  <p>Traceback:</p>
  
  <pre><code>Traceback (most recent call last):
    File "test_label.py", line 6, in &lt;module&gt;
      pylab.legend(fontsize='small')
    File "C:\swframe\python-V01-01\lib\site-packages\matplotlib\pyplot.py", line 2
  791, in legend
      ret =  gca().legend(*args, **kwargs)
    File "C:\swframe\python-V01-01\lib\site-packages\matplotlib\axes.py", line 447
  5, in legend
      self.legend_ = mlegend.Legend(self, handles, labels, **kwargs)
  TypeError: __init__() got an unexpected keyword argument 'fontsize'
  </code></pre>
  
  <p>Python: 2.7, Matplotlib: 1.1.0</p>
  
  <p>Edit: Note, I am not looking for alternative ways to set the font size. I want to know why this goes wrong.</p>