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/net/server/channel/handlers/DueyHandler.java

@@ -100,7 +100,8 @@ public final class DueyHandler extends AbstractMaplePacketHandler {
     @Override
     public final void handlePacket(SeekableLittleEndianAccessor slea, MapleClient c) {
     	if (!ServerConstants.USE_DUEY){
-    		return;
+            c.announce(MaplePacketCreator.enableActions());
+            return;
     	}
             
         byte operation = slea.readByte();
@@ -196,6 +197,7 @@ public final class DueyHandler extends AbstractMaplePacketHandler {
                 dp = dueypack;
                 if(dp == null) {
                     System.out.println("Error: Null Duey package!");
+                    c.announce(MaplePacketCreator.enableActions());
                     return;
                 }
                 
@@ -203,7 +205,6 @@ public final class DueyHandler extends AbstractMaplePacketHandler {
                     if (!MapleInventoryManipulator.checkSpace(c, dp.getItem().getItemId(), dp.getItem().getQuantity(), dp.getItem().getOwner())) {
                         c.getPlayer().dropMessage(1, "Your inventory is full");
                         c.announce(MaplePacketCreator.enableActions());
-                        
                         return;
                     } else {
                         MapleInventoryManipulator.addFromDrop(c, dp.getItem(), false);