Replace VPS swap by giving playground VPS addresses from production

[aither64]

Right now, VPS swap is needed, because playground is using different address ranges than production. So we use swap to put the new VPS into production and give it addresses from the original production VPS and vice versa. This operation was always very hard to grasp, explain and implement, so it should be retired.

We could instead ask the user for a purpose when creating/cloning a playground VPS: does he want a VPS that will later be put in production? Does he want to try something out and forget it? If the VPS is meant to be used in production, we'd give it addresses from production immediately and then it's simply a matter of migrating it onto production node -- IP addresses will be kept. It will make so much more sense to prepare a new VPS next to the old one, slowly move services over, etc. and not having to deal with IP changes.