title: Matplotlib `figure.show()` does not show anything on Mac OSX
body: <p>I'm using the latest matplotlib, version 2.0.0, installed via pip on Mac OSX Sierra. The problem is that the following example does not work as expected as no figure is shown. Note that I'm calling <code>show()</code> on the <code>figure1</code> object because I want to show only <code>figure1</code>. If I use <code>plt.show()</code> it works but it shows both <code>figure1</code> and <code>figure2</code> which I don't want.</p>
  
  <pre><code>import matplotlib.pyplot as plt
  
  figure1 = plt.figure()
  
  # I need figure2 for something else but I don't want to show it.
  figure2 = plt.figure()
  
  figure1.show()
  
  # The following would work, but I want to show
  # only figure1 and not also figure2.
  # plt.show()
  </code></pre>