Tweaks to RSB II, rename Red Bull, other changes

Robert's chance to reinflict Zombie after Scott heals it now starts at
50% (coin-flip odds) instead of 75%.  Crackdown moved to start of Phase
5 as a warning sign for Omni, and Robert no longer retaliates with Omni
when using Tonics on him as a Zombie in Phase 5.  He also now restores
his MP at the start of Phase 5 if he can.

Other changes:
* Red Bull is now called Revigor.
* Heal-to-damage conversion now kills Zombies outright if it brings them
to 0 HP, instead of transitioning them to Skeleton as before.
* Disarray now lasts exactly 3 turns.
* Skeleton status now cuts the victim's STR and MAG by half.
* Healing for Tonic items is now based on target's VIT stat and heals
less HP for higher-tier units.
* Desperation Slash now kills Skeletons.