AnimationKiller can detect, modify, and eliminate GIF89a animations.
This is done by examining/modifying GIF images as they pass through
Muffin.  GIF animations are typically implemented by using a special
application extension.  When found, AnimationKiller can do one of two
things:

* Modify the number of animation loops to something more desirable.
  Most animations loop forever and waste CPU resources.  Changing
  the number of loops to specific number limit the loop count
  to that number and then the animation will stop.

* Convert animations into broken images.  This is desirable if you
  don't want to see or download any animations.  In most cases
  the web browser will receive a truncated image file and display
  a broken image icon.

This filter has the following configurable preferences:

* AnimationKiller.maxLoops

  Modify the number of loops in the animation.
  Value of:
      -1   Display image and stop animation as soon as possible.
       0   Loop forever.
       1   Loop once.
       2   Loop twice, and so on.

* AnimationKiller.break

  Convert GIF animations into broken/truncated images.

