Interiors free of walls from above

Fixed

• Indoors and underground, the whole floor above you now disappears. Previously only the building you stood in was opened up, so terrain and the neighbouring houses' walls could draw across the interior — most visibly right after logging in.
• Gateways and archways now hide what stands over them as well. Until now a bare wall overhead, with no floor beneath it, left the storey above on screen.