title: Pyqtgraph RemoteGraphicsView and connecting signals
body: <p>So I'm currently using a RemoteGraphicsView in my application and I have included a LinearRegionItem
  into the view. I'm trying to connect the signal "sigRegionChanged" to a function in my application but I am getting the following errors depending on what I try.</p>
  
  <p>New Style Signal/Slot</p>
  
  <pre><code>my_region.sigRegionChanged.connect(self.my_function)
  </code></pre>
  
  <p>I get the following error that comes from the handler calls</p>
  
  <blockquote>
    <p>_pickle.PicklingError: Can't pickle : attribute lookup builtins.method failed</p>
  </blockquote>
  
  <p>Old style</p>
  
  <pre><code>self.connect(spot_area, QtCore.SIGNAL('sigRegionChanged'), self.spot_adjusted)
  </code></pre>
  
  <p>Gets an error about the spot_area being an ObjectProxy.</p>
  
  <p>Any ideas?</p>