New "buffering percentage" design

We need a new design for the playback buffer filling up. This isn't used very often, but for streaming media, it's imperative that we have something to show how full the playback buffer is. Once the buffer is full, playback will start.

Not to be confused with "download buffering" which preloads data from the network to disk for single files being played back. This is what the fill indicator on the seek bar will show when playing back a video from the "Apple Trailers" channel for example.

Can be replicated using totem http://samsonsheim.de:8000/demos.ogg (from http://dir.xiph.org/codecs/Theora)

From WIP GL port (it's just a label on top of the video)

Existing "buffering" animation: