title: Blender UV texture images not updating with Python API
body: <p>I'm updating a UV texture image in Blender 2.63 with a Python script on Ubuntu 12.04.  I can set the filepath property of the Image object, but the image is not refreshed.  I've tried calling update() and reload() members of the Image object without success.  Clicking the reload button from the GUI refreshes the image as expected.  Hovering over the reload button in the GUI shows that it uses bpy.ops.image.reload().  But when I call it, it returns CANCELLED status, I assume because there is some way to select the image object in the bpy.context module, which I have been unable to figure out how to accomplish.  Perhaps this is a bug?</p>
  
  <p>Relevant code below:</p>
  
  <pre><code># Update the filepath of a UV texture image
  obj = bpy.context.scene.objects.active
  image = obj.data.materials[0].texture_slots[0].texture.image
  image.filepath = '//myfile.png'
  
  # None of these work to refresh the image
  image.update ()
  image.reload ()
  bpy.ops.image.reload()
  </code></pre>