Multiple players issues

When I embed multiple instances of the player they will play simultaneously if I start more than one. Default behaviour should be that all playing instances should be paused if a new instance is played or unpaused.

Start by locating the player instance and play or unpause handling in the JavaScript source, then reproduce the behavior with two embedded players. Done means that starting or unpausing one instance pauses every other playing instance.

Written by the indexing model from the issue text.