cap luaentities table entries to valid coords on load

(in case the file gets corrupted on write?)

luaentity.lua

@@ -24,6 +24,22 @@ end
 local function read_entities()
 	local t = read_file()
 	for _, entity in pairs(t) do
+
+		local x=entity.start_pos.x
+		local y=entity.start_pos.y
+		local z=entity.start_pos.z
+
+		x=math.max(-30912,x)
+		y=math.max(-30912,y)
+		z=math.max(-30912,z)
+		x=math.min(30927,x)
+		y=math.min(30927,y)
+		z=math.min(30927,z)
+
+		entity.start_pos.x = x                 
+		entity.start_pos.y = y
+		entity.start_pos.z = z
+
 		setmetatable(entity, luaentity.registered_entities[entity.name])
 	end
 	return t