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/LakeFeature.cpp

@@ -24,8 +24,8 @@ bool LakeFeature::place(Level *level, Random *random, int x, int y, int z)
 
 	bool grid[16*16*8] = {0};
 
-	LevelGenerationOptions *levelGenOptions = NULL;
-	if( app.getLevelGenerationOptions() != NULL )
+	LevelGenerationOptions *levelGenOptions = nullptr;
+	if( app.getLevelGenerationOptions() != nullptr )
 	{
 		levelGenOptions = app.getLevelGenerationOptions();