Play tab and hook_view fixes

It has come to my attention that the play tab does not use hook_view. There is really no reason for this. In the video_view hook, it is possible to simply check the arg(2) argument to see if we should play the video. Then, all the requests get sent through hook_view, which calls the nodeapi hooks so other modules can modify the play page.

This patch removes the callback to node/nnn/play so it automatically reverts to the callback for node/nnn. Then it has video_view check to see if it should be playing the video rather than viewing the thumbnail. This is done at the same point as playinbody.

It also removes the thumbnail from the play page (which in my opinion should not be there.) But that part of the patch is really optional.