V022.01

- Added comments in every class.
- Changed attribute lives from int to byte.
- Now my game save startX too to scroll correctly when load game.
- Now my map has 2 parts. A background and a front. To make my player
walk behind the city lights.
- Implemented an array for collisions in MapIntro class.
- Player speed incremented.
- Constructor of sector class improved. Now receives the path of the
image.