solve bugs of memory leak and expanding menus
- resolve memory leak of config class
- resolve memory leak and level record when no child menu items exist
solve bugs of memory leaks
- resolve memory leak of config class
- resolve memory leak when no child menu items exist
implement basic rotation
massive code refactor
- move all stuff about menus into menu scene folder
- remove menu plane by rendering menus using 3d projection
massive code refactor
- put menus into a scene class from renderer
- delegate the rendering of menus to menu renderer