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/server/MapleItemInformationProvider.java

@@ -1294,6 +1294,11 @@ public class MapleItemInformationProvider {
     public boolean isCash(int itemId) {
         return itemId / 1000000 == 5 || getEquipStats(itemId).get("cash") == 1;
     }
+    
+    public boolean isRateCoupon(int itemId) {
+        int itemType = itemId / 1000;
+        return itemType == 5211 || itemType == 5360;
+    }
 
     public Collection<Item> canWearEquipment(MapleCharacter chr, Collection<Item> items) {
         MapleInventory inv = chr.getInventory(MapleInventoryType.EQUIPPED);