Initial Release

_- Added the totem-of-undying immortality exploit from Spoke's Purgatory Prison video.

• Players can be granted "immortal" status, intercepting lethal damage and auto-equipping a Totem of Undying.
• Added /unstable immortality add and /unstable immortality remove commands.
• Added unstable.admin permission to control access.
• Immortal player list now persists across server restarts via config.yml._