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/Model.h

@@ -23,8 +23,8 @@ public:
 	virtual void render(shared_ptr<Entity> entity, float time, float r, float bob, float yRot, float xRot, float scale, bool usecompiled) {}
 	virtual void setupAnim(float time, float r, float bob, float yRot, float xRot, float scale, shared_ptr<Entity> entity, unsigned int uiBitmaskOverrideAnim=0) {}
 	virtual void prepareMobModel(shared_ptr<LivingEntity> mob, float time, float r, float a) {}
-	virtual ModelPart *getRandomModelPart(Random random) {return cubes.at(random.nextInt((int)cubes.size()));}
-	virtual ModelPart * AddOrRetrievePart(SKIN_BOX *pBox) { return NULL;}
+	virtual ModelPart *getRandomModelPart(Random random) {return cubes.at(random.nextInt(static_cast<int>(cubes.size())));}
+	virtual ModelPart * AddOrRetrievePart(SKIN_BOX *pBox) { return nullptr;}
 
 	void setMapTex(wstring id, int x, int y);
 	TexOffs *getMapTex(wstring id);