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.Client/PauseScreen.cpp

@@ -54,12 +54,12 @@ void PauseScreen::buttonClicked(Button button)
             minecraft->level->disconnect();
         }
 
-        minecraft->setLevel(NULL);
+        minecraft->setLevel(nullptr);
         minecraft->setScreen(new TitleScreen());
     }
     if (button.id == 4)
 	{
-        minecraft->setScreen(NULL);
+        minecraft->setScreen(nullptr);
  //       minecraft->grabMouse();		// 4J - removed
     }
 
@@ -88,7 +88,7 @@ void PauseScreen::render(int xm, int ym, float a)
 	{
         float col = ((visibleTime % 10) + a) / 10.0f;
         col = Mth::sin(col * PI * 2) * 0.2f + 0.8f;
-        int br = (int) (255 * col);
+        int br = static_cast<int>(255 * col);
 
         drawString(font, L"Saving level..", 8, height - 16, br << 16 | br << 8 | br);
     }