Enchantments

Note: It's my first time doing something with C++
This is unsafe and was originally removed because of potential crashes - if a player disconnects before the arrow hits an entity, the pointer becomes invalid, and if the arrow *does* hit an entity, a crash may occur.

Instead, cProjectileEntity.h has a `CreatorData` structure; add a cEnchantments member variable to that, and then initialise it in cProjectileEntity.cpp - there are already examples there to follow.