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/Direction.cpp

@@ -65,7 +65,7 @@ int Direction::RELATIVE_DIRECTION_FACING[4][6] =
 
 int Direction::getDirection(double xd, double zd)
 {
-	if (Mth::abs((float) xd) > Mth::abs((float) zd))
+	if (Mth::abs(static_cast<float>(xd)) > Mth::abs(static_cast<float>(zd)))
 	{
 		if (xd > 0)
 		{