Added !nolynch/abstain command

Features:
- Added var.NO_LYNCH to keep track of no-lynchers
- Tweaked hurry_up to count not-lynching players
- Makes day end without a lynch if enough players abstain
- Consider pacifists and not-lynching as equal for lynching calculation
(in chk_decision and hurry_up)
- Add "x players have refrained from voting" in !votes
- Added actual nolynch/abstain command, which is a toggle to no_lynch or
not
- Make !voting automatically remove the player from the no-lynchers
- Make !retract remove the player from no-lynchers