Refactor & More.

Changed the entity system to utilize mix-ins.

Added instanced sprites.

Texture support.

include/Game/entity/DemoGameHud.h

@@ -0,0 +1,14 @@
+#include <Engine/types/entity/Hud.h>
+
+namespace Game {
+    class DemoGameHud;
+}
+
+class Game::DemoGameHud : public Engine::Hud {
+public:
+    void Render() override;
+public:
+    DemoGameHud() : Hud() {}
+};
+
+