Teleporting the cursor when at the edge of the screen

[jespertheend]

Some software like Blender and Unity warp the cursor to the opposite edge of the screen and keep showing the cursor.
This is a better user experience in some cases because the cursor stays visible and it is where you expect it to be after making a short movement.

Take https://pointer-lock-dragging-demo.glitch.me/ for instance. It could be desirable if the cursor stayed visible and moved along with the red circle. This is even more the case when holding a key rather than clicking and dragging. (You can hold spacebar in this demo)

Perhaps an extra flag that can be passed to requestPointerLock() would already be enough for this. Making it possible for developers to set the location of the circle will probably allow for abuse.

This is similar to #27 except that the pointer is teleported rather than clipped.