!time: Fix for time command.

- Checks time remaining for day based on the number of players who were alive at the start of the day
- Added check to make sure timers are enabled/active
- Added debug mode override for SHORT_DAY_LIMIT_CHANGE and  SHORT_DAY_LIMIT_WARN

Game log where !time gave some bad values: http://pastebin.com/1aHQPAp9