Add some features to make the game easier

[GentlePurpleRain]

• Shiro will now automatically provide the colour of a guess right after it is made.
• Shiro keeps track of turns and the number of guesses, so you can always ask whose turn it is or how many guesses you have left (!who or !guesses) (one is an alias for the other)
• You can't post a clue or a guess unless it's your turn. Shiro will ignore any clues/guesses provided out of turn.
• Remove the !undo command, since it is now useless (Shiro provides an immediate response, after which it's too late to undo). Not allowing people to answer out of turn should eliminate the need for this.
• Add a little snark when you guess the other team's word.
• Update the !blame command to randomly blame someone who's playing the game.
• Disallow (and point out) invalid guesses (not on the board)