Also put library code in a library directory

The new version of PaymentServer has incompatible changes that require this.

Also some refactoring to make this easier in the future, steps towards
unifying production and testing definitions, and start of docs for the whole thing.

Also, a hostId as required by zfs.

And account for the odd-host-out. :/  See if you can spot it.

The layer above will have to make sure that it is.