Participants management

Singles
- Connection to the competition: 1 user per participant
- Participant's name can be different from user's name (i.e. a nickname or a team name)

Doubles
- Connection to the competition: 2 users per each doubles team
- Doubles team names can be different from users names

Teams
- Team pages with rosters
- Connection to the competition: all the members of each team
- Custom secondary rankings (like goal scorers, best players, and so on)

Number of participants
You can change the number of participants whenever you want. Also after the competition has started.
