More flexible Prev/Next weapon

[wisien92]

While expanding the code I decided to add more slots for items (Meele firs aid etc.). Prev/Next code striked me as kinda strage, and I replaced it with:

ASWeapon* NextWeapon = Inventory[CurrentWeaponIndex + 1 < Inventory.Num() ? CurrentWeaponIndex + 1 : 0];

ASWeapon* PrevWeapon = Inventory[CurrentWeaponIndex - 1 >= 0 ? CurrentWeaponIndex - 1 : Inventory.Num() - 1];

I think it's easier to understand and you don't need to "touch" it in future (previous code had some issues with eg. 3 items in inventory).