[B] Fix two Mismatch with Scoreboard command

The issue : 

First:
When you add only one player in a scoreboard teams , bukkit display ' and PlayerName' , if addedPlayers have only one player , just display his name.

Second: Scoreboard objectives allow all criteria, but we need to check if the criteria is correct!

PR BreakDown : just fix that

Best regard,

Xephi