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/ByteArrayInputStream.cpp

@@ -114,5 +114,5 @@ int64_t ByteArrayInputStream::skip(int64_t n)
 
 ByteArrayInputStream::~ByteArrayInputStream()
 {
-	if(buf.data != NULL) delete [] buf.data;
+	if(buf.data != nullptr) delete [] buf.data;
 }