Made Assets singleton final
Slight reorganization of code.
Cleaned/optimized the pan trigger code
Fully implemented scene transitioning. Can go from scene1 to scene2 and vice versa.

Added transitioning game state
Added helper methods for checking (State | State) and (State & State) in the GameState
Blocked input when transitioning between scenes
Changed player step logging to verbose logging
Added a method to stop rain sounds
Renamed Scene.java to Scene1 to better reflect that it's the first scene and to prepare for Scene abstraction later.
Added support for scene preloading