Add anti-grief to water in danger ores

[Jayefuu]

Just leaving this here so I don't forget.

Danger ores water keeps getting griefed. I need to add a check when landfill is used. Possible fixes:

1. Detect when landfill placed and not allow it within X, Y of spawn
2. Detect when landfill and do an entity search for nearby pumps, disallow landfill use if pumps are nearby.

I think I prefer (1), there's no good reason to fill in the water near spawn.

[grilledham]

Note: We do have the feature where players can remove landfill with the deconstruction planner, so this might not be needed.

I prefer 1) and wouldn't object to it in danger ores. It does have the advantage that players don't need to know about the landfill remover feature. The downside is that players may genuinely want to landfill the spawn water mid-late game as the bus normally ends up through spawn.

[Jayefuu]

What about just limiting use of landfill to regulars and auto-trusted?