add custom event that fires on all window resize events

src/Display.cpp

@@ -171,12 +171,15 @@ void sb::Display::respond(SDL_Event& event)
             sb::Log::Level level = event.window.event == SDL_WINDOWEVENT_RESIZED ? sb::Log::INFO : sb::Log::DEBUG;
             sb::Log::log(message, level);
 
-            /* Resize the GL viewport */
+            /* Set the GL viewport to fill the window (this should probably be optional...) */
             if (SDL_GL_GetCurrentContext() != nullptr)
             {
                 glViewport(0, 0, event.window.data1, event.window.data2);
                 sb::Log::gl_errors("After glViewport resize");
             }
+
+            /* Send a general window resize event to the framework */
+            Delegate::post("window resize");
         }
     }
 }