Experimental Character/Client Closure + Morph & Crash skills patch

Player Trade is now enabled inside PQ & events.
Refactored minigame code, now using enums rather than strings for logistics.
Fixed Transformations not applying stat buffs properly.
Warrior's Crash skills now acts accordingly with their description (rather than applying all combined debuffs).
Added a server flag for Crash skills, to apply mob immunity debuffs as well.
Fixed Shark Wave not stacking charges.
Dragon Roar now properly stuns the mobs (stun effect won't show up, though).
Refactored empty method on MapleCharacter, now freeing more resources.
[EXPERIMENTAL] Upon lifetime's end of the object, empty function will be called alongside MapleClient's clear, should issues arise from that, it's TBD.

src/constants/ServerConstants.java

@@ -140,6 +140,7 @@ public class ServerConstants {
     
     //Other Skills Configuration
     public static final boolean USE_FAST_REUSE_HERO_WILL = true;//Greatly reduce cooldown on Hero's Will.
+    public static final boolean USE_ANTI_IMMUNITY_CRASH = true; //Crash skills additionally removes the mob's invincibility buffs.
     
     //Character Configuration
     public static final boolean USE_ADD_SLOTS_BY_LEVEL = true;  //Slots are added each 20 levels.