title: Matplotlib Quiver memory leak
body: <p>I have created quite a nice visualization program using Qt as the interface layer and matplotlib to draw much of the content.  I use contour and countourf as well as text and lines and never run into problems with releasing objects. </p>
  
  <p>As soon as I start calling Axes.quiver I get leaks.  With the size of the dataset it adds up quickly.  The following code demonstrates the problem:</p>
  
  <pre><code>from pylab import *
  from numpy import ma
  import time
  
  X,Y = meshgrid( arange(0,2*pi,.04),arange(0,2*pi,.04) )
  U = cos(X)
  V = sin(Y)
  
  fig = figure()
  ax = fig.add_axes([0.1,0.1,0.8,0.8])
  for i in range(90):
      Q = ax.quiver( U, V)
      time.sleep(0.2)
      Q.remove()
  </code></pre>
  
  <p>I know this simple snippet isnt drawing to screen (leak becomes worse then).  </p>
  
  <p>Q has a sys.getrefcount of 4 so nothing I am able to do seems to get rid of it.  Calls to fig and ax clear only reduce the refcount to 2.  Quiver draws the image i want, but I am completely out of ideas.</p>
  
  <p>My code is much more complex than this.  I have tried completely replacing the axes objects but that doesnt help.  I really am not free to replace the Figure instance.</p>