Moved UniqueEffectType to constructor and removed setUnique().

Changed SetUnit / SetActive to be more versatile and added setEnabled.

 - SetUnit(unit) Sets unit and enables (when non-null).
 - SetUnit(unit, bool enable) Choose to enable or not.

 - SetEnabled is for buffs (or similar) to disable abilities. (Won't clear Unit but will remove from Unique Manager)

 - SetActive is for activating/deactivating unique effects. (Won't clear Unit or remove from Unique Manager. Does nothing if disabled.)
Bug fix - no result would cause a null pointer exception. This should never happen though, only if another error prevents anything being logged.