Partial fix for issue #288.
Partial fix for issue #288.

- For registered users, the 'skip' command now stores the registered name
  of the user instead of the user's current nick
- Unregistered users still won't have tracking for 'skip' across different
  nicks
- Made skip() an 'onlyInChannel' command
- Partial refactoring of skip() method
- Small fix for kaosRemainingCommand

tannn/TriviaTime,tannn/TriviaTime,tannn/TriviaTime