Modernize project codebase (#906)

* 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

* Add safety checks and fix a issue with vector going OOR

Minecraft.World/ClientSideMerchant.cpp

@@ -7,8 +7,8 @@ ClientSideMerchant::ClientSideMerchant(shared_ptr<Player> source, const wstring
 {
 	this->source = source;
 	// 4J Stu - Need to do this after creating as a shared_ptr
-	container = NULL; //new MerchantContainer(source, this);
-	currentOffers = NULL;
+	container = nullptr; //new MerchantContainer(source, this);
+	currentOffers = nullptr;
 	m_name = name;
 }