8 hours, turrets and pick ups tile occupation.
Turrets now spawn dead center on a tile. All calls for the creation of a turret warp in effect have been hunter down and replaced by function in the spawn director that takes a location and finds the nearest unoccupied tile to that location, spawns the effect there, notes that tile as occupied, and passes the occupation information to the effect. The effect then passes the info to the turret, the turret clears the tiles when it is destroyed.
When the turret is spawned via walker building a tile assignment function in the spawn director is run that can fail. The assignment fails if the closest unoccupied tile is not the closest tile (no attention paid to whether it is occupied) or an adjacent to the closest tile. If the attempt fails, a new pick up is instantiated as would happen if the old system was threatening to go infinite.
Stationary pick ups now occupy the tiles on which they are instantiated. They release these tiles when collected or made mobile.
Still Shooters and FSJ to do.