first frame preview load only

[netpipe]

while viewing http://headlikeanorange.tumblr.com/ more than just the first frame seems to get loaded on the GIF files causing the website to take a very long time to load. would be neat to have just the preview image without any of the animation buffered unless hovered over.

[simonlindholm]

Agreed, but it's more or less impossible with the way the addon is implemented... :(

(Duplicate of #21.)