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/SetDisplayObjectivePacket.cpp

@@ -13,7 +13,7 @@ SetDisplayObjectivePacket::SetDisplayObjectivePacket(int slot, Objective *object
 {
 	this->slot = slot;
 
-	if (objective == NULL)
+	if (objective == nullptr)
 	{
 		objectiveName = L"";
 	}