Add option for setting default max vaults of a faction.

src/main/java/com/massivecraft/factions/Conf.java

@@ -358,6 +358,7 @@ public class Conf {
 
     // faction-<factionId>
     public static String vaultPrefix = "faction-%s";
+    public static int defaultMaxVaults = 0;
 
     public static Backend backEnd = Backend.JSON;
 

src/main/java/com/massivecraft/factions/zcore/persist/MemoryFaction.java

@@ -322,6 +322,7 @@ public abstract class MemoryFaction implements Faction, EconomyParticipator {
         this.money = 0.0;
         this.powerBoost = 0.0;
         this.foundedDate = System.currentTimeMillis();
+        this.maxVaults = Conf.defaultMaxVaults;
     }
 
     public MemoryFaction(MemoryFaction old) {