Detect umode +g and request /accepting the bot

[Mikaela]

Background: I played similar game IRL last night and thought I could play the IRC version again in a long time as I had nothing else to do.

Issue: I joined the game with !j. Then during the night I got umode +g notice and @nyuszika7h told me to see my role with !myrole when I asked for replay of whatever the message was. It was that I am the seer and should have seen someone so I was idle and day came.

Possible solution: when people join the game, send them a test message and if there is umode +g, ask for the player to /accept the bot and refuse to start the game until that is done. Maybe require /msg bot whatever for noticing that it has been accepted.

[ghost]

See #135. (Are you ever going to complete that, @ilbelkyr?)

[Mikaela]

I think this should stay open as that is closed, alternatively that should be reopened.