Add UI Control Elements

1. Set portrait only in project file.
2. Add #define ENABLE_UI in pch file to control UI display.
3. Add custom modified ECSSlidingView library.
4. Add custom modified PullableView library.
4. Add Mock Assets.
6. Add ToBuyViewController.
7. Implement background menu.
8. Implement slideout menu.
9. Implement table cell menu.