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/ChunkPos.cpp

@@ -16,8 +16,8 @@ int64_t ChunkPos::hashCode(int x, int z)
 int ChunkPos::hashCode()
 {
 	int64_t hash = hashCode(x, z);
-	int h1 = (int) (hash);
-	int h2 = (int) (hash >> 32l);
+	const int h1 = static_cast<int>(hash);
+	const int h2 = static_cast<int>(hash >> 32l);
 	return h1 ^ h2;
 }