SPIGOT-840, SPIGOT-2522: [Draft] Add EntityPotionEffectChangeEvent

Discussion ongoing in PR #449

By: kaenganxt <kaenganxt@mc-anura.de>

paper-server/nms-patches/EntityHuman.patch

@@ -51,6 +51,15 @@
      public EntityHuman(World world, GameProfile gameprofile) {
          super(EntityTypes.PLAYER, world);
          this.cd = ItemStack.a;
+@@ -184,7 +208,7 @@
+         ItemStack itemstack = this.getEquipment(EnumItemSlot.HEAD);
+ 
+         if (itemstack.getItem() == Items.TURTLE_HELMET && !this.a(TagsFluid.a)) {
+-            this.addEffect(new MobEffect(MobEffects.WATER_BREATHING, 200, 0, false, false, true));
++            this.addEffect(new MobEffect(MobEffects.WATER_BREATHING, 200, 0, false, false, true), org.bukkit.event.entity.EntityPotionEffectEvent.Cause.TURTLE_HELMET); // CraftBukkit
+         }
+ 
+     }
 @@ -369,7 +393,8 @@
  
          if (this.world.getDifficulty() == EnumDifficulty.PEACEFUL && this.world.getGameRules().getBoolean("naturalRegeneration")) {