Project modernization (#630)

* Fixed boats falling and a TP glitch #266

* Replaced every C-style cast with C++ ones

* Replaced every C-style cast with C++ ones

* Fixed boats falling and a TP glitch #266

* Updated NULL to nullptr and fixing some type issues

* Modernized and fixed a few bugs

- Replaced most instances of `NULL` with `nullptr`.
- Replaced most `shared_ptr(new ...)` with `make_shared`.
- Removed the `nullptr` macro as it was interfering with the actual nullptr keyword in some instances.

* Fixing more conflicts

* Replace int loops with size_t and start work on overrides

Minecraft.World/DamageEnchantment.cpp

@@ -51,7 +51,7 @@ int DamageEnchantment::getDescriptionId()
 
 bool DamageEnchantment::isCompatibleWith(Enchantment *other) const
 {
-	return dynamic_cast<DamageEnchantment *>(other) == NULL;
+	return dynamic_cast<DamageEnchantment *>(other) == nullptr;
 }
 
 bool DamageEnchantment::canEnchant(shared_ptr<ItemInstance> item)