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/StoneMonsterTile.cpp

@@ -48,7 +48,7 @@ void StoneMonsterTile::destroy(Level *level, int x, int y, int z, int data)
 			// Also limit the amount of silverfish specifically
 			if(level->countInstanceOf( eTYPE_SILVERFISH, true) < 15 )
 			{
-				shared_ptr<Silverfish> silverfish = shared_ptr<Silverfish>(new Silverfish(level));
+				shared_ptr<Silverfish> silverfish = std::make_shared<Silverfish>(level);
 				silverfish->moveTo(x + .5, y, z + .5, 0, 0);
 				level->addEntity(silverfish);
 
@@ -106,7 +106,7 @@ shared_ptr<ItemInstance> StoneMonsterTile::getSilkTouchItemInstance(int data)
 	{
 		tile = Tile::stoneBrick;
 	}
-	return shared_ptr<ItemInstance>(new ItemInstance(tile));
+	return std::make_shared<ItemInstance>(tile);
 }
 
 int StoneMonsterTile::cloneTileData(Level *level, int x, int y, int z)