NPC: Changed general issue with names. Now names are a dedicated variable, not anymore a nametag.

NPC names aren't visible anymore.
Spawner: Added NPC statistics to plotmarkers.
Add statistics-based spawning for a more balanced, family-type spawning of NPCs.

dialogue.lua

@@ -296,7 +296,7 @@ function npc.dialogue.process_dialogue(self, dialogue, player_name)
 
 	-- Send dialogue line
 	if dialogue.text then
-		minetest.chat_send_player(player_name, self.name..": "..dialogue.text)
+		minetest.chat_send_player(player_name, self.npc_name..": "..dialogue.text)
 	end
 
   -- Check if dialogue has responses. If it doesn't, unlock the actions