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/Chicken.cpp

@@ -143,7 +143,7 @@ shared_ptr<AgableMob> Chicken::getBreedOffspring(shared_ptr<AgableMob> target)
 	// 4J - added limit to chickens that can be bred
 	if( level->canCreateMore( GetType(), Level::eSpawnType_Breed) )
 	{
-		return shared_ptr<Chicken>(new Chicken(level));
+		return std::make_shared<Chicken>(level);
 	}
 	else
 	{