Add new attack animation for the player (knight)

- Refactor the structure of user commands
- Change the team to keep track of points (and not only players)
- Fix a bug that caused the flags to be counted twice
- Update configuration template
- Disable the sound effects (until the final ones are ready)
- Remove temporary maps and associated data
- Update how to section in index.html
Merge branch 'release/0.13.0'