P0-A4: Part 568: Debugging, Refactoring

The improvements to the persistent location system seem to be working reasonably well.

I still need to test them extensively, but everything seems to be working very well so far. Only the player control object is stored with 64-bit accuracy, but most of the other objects are created procedurally, so their position doesn’t need to be in 64-bit coordinates.

I need to spend some time debugging and testing this system further, before I work on the next feature.