Smoother map scrolling

[Hachitus]

The map should be movable with smoother animation and something where we can be sure the white hidden areas outside viewport won't be shown and there is time to populate them. Now it is just simply moves the same way as the player drags the map.

I think we should implement the smoother mobile way of dragging, so a bit of acceleration and deceleration in the dragging and possibly in mobiles use velocity parameter too.