Add 2 new roles: doctor and alpha wolf (and rename wolf cub -> wolf pup)

Doctor is on the village team, and has a number of immunizations they can give out during the day. An immunized lycan reverts a normal villager, and anyone that is immunized will die instead of turning into a wolf if they are bitten by the alpha wolf. Beware, however, because attempting to immunize someone already bitten will simply speed up the process of them becoming a wolf!

Alpha wolf has a once-per-game ability where they can bite the wolves' target instead of killing them following the death of a werewolf during the day. The bitten person will subsequently turn into a wolf in 3 nights. For each wolf that dies during the transformation period, the timer is reduced by 1 night.

Wolf Cub renamed to Wolf Pup because baby wolves are called pups in real life. This will need a short UPDATE to fix stats:
```
UPDATE roles SET role = 'wolf pup' WHERE role = 'wolf cub';
UPDATE rolestats SET role = 'wolf pup' WHERE role = 'wolf cub';
```