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.Client/ModelHorse.cpp

@@ -252,7 +252,7 @@ void ModelHorse::render(shared_ptr<Entity> entity, float time, float r, float bo
 	bool largeEars = type == EntityHorse::TYPE_DONKEY || type == EntityHorse::TYPE_MULE;
 	float sizeFactor = entityhorse->getFoalScale();
 
-	bool rider = (entityhorse->rider.lock() != NULL);
+	bool rider = (entityhorse->rider.lock() != nullptr);
 
 	if (saddled)
 	{
@@ -401,7 +401,7 @@ void ModelHorse::prepareMobModel(shared_ptr<LivingEntity> mob, float wp, float w
 	float openMouth = entityhorse->getMouthAnim(a);
 	bool tail = entityhorse->tailCounter != 0;
 	bool saddled = entityhorse->isSaddled();
-	bool rider = entityhorse->rider.lock() != NULL;
+	bool rider = entityhorse->rider.lock() != nullptr;
 	float bob = mob->tickCount + a;
 
 	float legAnim1 = cos((wp * 0.6662f) + 3.141593f);