When the window is resized, the viewport is automatically reset.

This resolves lots of confusion around resizable windows.  Most people don't expect a viewport to be implicitly set when the renderer is created and then not to be reset to the window size if the window is resized.

Added common test command line parameters --logical WxH and --scale N to test the render logical size and scaling APIs.

src/render/SDL_sysrender.h

@@ -123,7 +123,6 @@ struct SDL_Renderer
     /* The window associated with the renderer */
     SDL_Window *window;
     SDL_bool hidden;
-    SDL_bool resized;
 
     /* The logical resolution for rendering */
     int logical_w;