Spells: Cures "passing through" on successful dispel

[Technique]

When a cure spell removes a buff with poison/disease counters, it continues to act on subsequent buffs as if its effect_value hasn't been decremented.

Probably the simplest example demonstrating this bug is Cure Disease (-1 counter) removing both Sicken (1) and Infectious Cloud (1) in a single cast.

Another is Counteract Poison (-4,-4) removing both Tainted Breath (5) and Venom of the Snake (7) in a single cast.