Merge play and pause buttons
This issue was created automatically from an original Mantis Issue. Further discussion may take place here.
As I have been playing with the new animation controls in PV, I've noticed that it's awkward to start and stop the animation quickly.
Let's merge the play and pause buttons into one button. When the animation is not running it shows the play icon, and when the animation is running it shows the pause icon. This would allow use to start and stop the animation without moving the mouse.
Note that both Windows Media Player and iTunes follow this convention.