Modified the formats of stage scripts.

[MOD] Modified the formats of stage scripts.
Added GameMap and GameScript.

[NEW] Added GameMap.
[NEW] Added GameScript.
[MOD] Moved the control of display to GameMap.
Now the key binding occured in GameStage.

[NEW] Added GameMap.update().
[NEW] Added GameScript.update().
[NEW] Added GameStage.update().
[MOD] Now the key binding occured in GameStage.
[FIX] Fixed the wrong formats of scripts and stages.