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/TallGrass.cpp

@@ -81,7 +81,7 @@ int TallGrass::getResourceCountForLootBonus(int bonusLevel, Random *random)
 
 void TallGrass::playerDestroy(Level *level, shared_ptr<Player> player, int x, int y, int z, int data)
 {
-    if (!level->isClientSide && player->getSelectedItem() != NULL && player->getSelectedItem()->id == Item::shears->id)
+    if (!level->isClientSide && player->getSelectedItem() != nullptr && player->getSelectedItem()->id == Item::shears->id)
 	{
         player->awardStat(
 			GenericStats::blocksMined(id), 
@@ -89,7 +89,7 @@ void TallGrass::playerDestroy(Level *level, shared_ptr<Player> player, int x, in
 			);
 
         // drop leaf block instead of sapling
-        popResource(level, x, y, z, shared_ptr<ItemInstance>(new ItemInstance(Tile::tallgrass, 1, data)));
+        popResource(level, x, y, z, std::make_shared<ItemInstance>(Tile::tallgrass, 1, data));
     }
 	else
 	{