Fixed some error with WorldGuard.
Fixed nausea not working fine.
Fixed spectators not being ignored by some vampire tasks (thanks for reporting the bug, MrJarousek).
Added WorldGuard flag to create vampire-friendly areas (sugested by mr_coffee, thanks). The new flag is irradiate-vampires (ALLOW by default). Denying it will cause that all vampires in the region won't be affected by Sun debuffs.