MapleCouponInstaller + EXP/DROP Coupon System

Added mechanics for the EXP/DROP cash coupons (such as enabling
out-of-time active coupons via command and automatic update of active
ones over the designed interval). Created MapleCouponInstaller as means
to gather info about the coupon intervals and rates from the WZs (the
generated SQL table is already updated on the db_database.sql file).

src/client/inventory/MapleInventory.java

@@ -39,12 +39,14 @@ import server.MapleItemInformationProvider;
  * @author Matze
  */
 public class MapleInventory implements Iterable<Item> {
+    private MapleCharacter owner;
     private Map<Short, Item> inventory = new LinkedHashMap<>();
     private byte slotLimit;
     private MapleInventoryType type;
     private boolean checked = false;
     
-    public MapleInventory(MapleInventoryType type, byte slotLimit) {
+    public MapleInventory(MapleCharacter mc, MapleInventoryType type, byte slotLimit) {
+        this.owner = mc;
         this.inventory = new LinkedHashMap<>();
         this.type = type;
         this.slotLimit = slotLimit;
@@ -91,13 +93,13 @@ public class MapleInventory implements Iterable<Item> {
     }
 
     public int countById(int itemId) {
-        int possesed = 0;
+        int qty = 0;
         for (Item item : inventory.values()) {
             if (item.getItemId() == itemId) {
-                possesed += item.getQuantity();
+                qty += item.getQuantity();
             }
         }
-        return possesed;
+        return qty;
     }
 
     public List<Item> listById(int itemId) {
@@ -122,7 +124,7 @@ public class MapleInventory implements Iterable<Item> {
         if (slotId < 0 || item == null) {
             return -1;
         }
-        inventory.put(slotId, item);
+        addSlot(slotId, item);
         item.setPosition(slotId);
         return slotId;
     }
@@ -131,7 +133,7 @@ public class MapleInventory implements Iterable<Item> {
         if (item.getPosition() < 0 && !type.equals(MapleInventoryType.EQUIPPED)) {
             return;
         }
-        inventory.put(item.getPosition(), item);
+        addSlot(item.getPosition(), item);
     }
 
     public void move(short sSlot, short dSlot, short slotMax) {
@@ -193,8 +195,24 @@ public class MapleInventory implements Iterable<Item> {
         }
     }
 
+    public void addSlot(short slot, Item item) {
+        inventory.put(slot, item);
+        
+        if(MapleItemInformationProvider.getInstance().isRateCoupon(item.getItemId())) {
+            System.out.println("reformulating");
+            owner.revertCouponRates();
+            owner.setCouponRates();
+        }
+    }
+    
     public void removeSlot(short slot) {
-        inventory.remove(slot);
+        Item item = inventory.remove(slot);
+        
+        if(item != null && MapleItemInformationProvider.getInstance().isRateCoupon(item.getItemId())) {
+            System.out.println("reformulating");
+            owner.revertCouponRates();
+            owner.setCouponRates();
+        }
     }
 
     public boolean isFull() {