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/MushroomCowRenderer.cpp

@@ -42,7 +42,7 @@ void MushroomCowRenderer::additionalRendering(shared_ptr<LivingEntity> _mob, flo
 	glPopMatrix();
 
 	glPushMatrix();
-	((QuadrupedModel *) model)->head->translateTo(1 / 16.0f);
+	static_cast<QuadrupedModel *>(model)->head->translateTo(1 / 16.0f);
 	glScalef(1, -1, 1);
 	glTranslatef(0, 0.75f, -0.2f);
 	glRotatef(12, 0, 1, 0);