Player can join with it's own informations

[rzym-on]

For now, only master of the session is allowed to add/edit/delete new players and spectators.

Need to implement solution, where player can join to session with it's own name, color and sex.
StartPage will be having 3 options:

1. Game master
2. Spectator (for TVs, and other passive spectators)
3. Player (chose name, color, sex)

When player fill up neccessary fields, game master will aprove or deny incoming player with informations in created session. After that, player will become spectator (won't be able to edit these informations). Maybe in the future there will be some more improvements.

Also it'll be convenient to store player information in LocalStorage for future games.