Player: Resize video when SWF resizes

If the DOM element containing the SWF (and consequently the SWF itself)
resizes, then we must re-scale the video to the new area of the stage
so it is neatly centered and of correct size.

Change-Id: I04511e7203d6374496681493f9d0a461ab3be2fe
Merge pull request #82 from noseglid/video_resize

Player: Resize video when SWF resizes