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/SignTile.cpp

@@ -26,7 +26,7 @@ void SignTile::updateDefaultShape()
 
 AABB *SignTile::getAABB(Level *level, int x, int y, int z)
 {
-	return NULL;
+	return nullptr;
 }
 
 AABB *SignTile::getTileAABB(Level *level, int x, int y, int z)
@@ -79,7 +79,7 @@ shared_ptr<TileEntity> SignTile::newTileEntity(Level *level)
 {
 	//try {
 	// 4J Stu - For some reason the newInstance wasn't working right, but doing it like the other TileEntities is fine
-	return shared_ptr<TileEntity>( new SignTileEntity() );
+	return std::make_shared<SignTileEntity>();
 	//return dynamic_pointer_cast<TileEntity>( clas->newInstance() );
 	//} catch (Exception e) {
 	// TODO 4J Stu - Exception handling