Call PlayerMoveEvent

Based on JeromSar's code, with several improvements

Particularly, the event isn't called if both locations are equal. This decreases event spam but not as much as craftbukkit does - that would require keeping state in the player of the last sent move event, which would be awkward.

[MiniPython][] test plugin here: <https://gist.github.com/dequis/0c05ebfa93cf9984f877>

[MiniPython]: https://github.com/SpaceManiac/MiniPython