Synchronize player locations

[KieronWiltshire]

Would it be possible to add in other things such as waypoints and player locations?

[Protonull]

Would need to ask @wingzero54 first as to whether either/both of those things are legal and to what extent.

[Gjum]

I would accept pull requests that implement this, but current priorities are improving the performance and other issues that appeared during use.

Waypoint synchronization is tracked in #35 already so I've renamed this to be about player locations specifically. For other requests please open new issues individually.