Modernize project codebase (#906)

* 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

* Add safety checks and fix a issue with vector going OOR

Minecraft.Client/Durango/Iggy/gdraw/gdraw_d3d11.h

@@ -41,7 +41,7 @@ IDOC extern GDrawFunctions * gdraw_D3D11_CreateContext(ID3D11Device *dev, ID3D11
    There can only be one D3D GDraw context active at any one time.
 
    If initialization fails for some reason (the main reason would be an out of memory condition),
-   NULL is returned. Otherwise, you can pass the return value to IggySetGDraw. */
+   nullptr is returned. Otherwise, you can pass the return value to IggySetGDraw. */
 
 IDOC extern void gdraw_D3D11_DestroyContext(void);
 /* Destroys the current GDraw context, if any. */
@@ -69,7 +69,7 @@ IDOC extern void gdraw_D3D11_SetTileOrigin(ID3D11RenderTargetView *main_rt, ID3D
    If your rendertarget uses multisampling, you also need to specify a shader
    resource view for a non-MSAA rendertarget texture (identically sized to main_rt)
    in non_msaa_rt. This is only used if the Flash content includes non-standard
-   blend modes which have to use a special blend shader, so you can leave it NULL
+   blend modes which have to use a special blend shader, so you can leave it nullptr
    if you forbid such content.
 
    You need to call this before Iggy calls any rendering functions. */