Fixed platform differences and switched windows size values from hard coded to use a common set of variables

Samples/basic/sfml2/src/main.cpp

@@ -45,7 +45,14 @@
 
 int main(int argc, char **argv)
 {
-	sf::RenderWindow MyWindow(sf::VideoMode(800, 600), "libRocket with SFML2", sf::Style::Close);
+#ifdef ROCKET_PLATFORM_WIN32
+        DoAllocConsole();
+#endif
+
+        int window_width = 1024;
+        int window_height = 768;
+
+	sf::RenderWindow MyWindow(sf::VideoMode(window_width, window_height), "libRocket with SFML2", sf::Style::Close);
 	MyWindow.setVerticalSyncEnabled(true);
 
 #ifdef ENABLE_GLEW