MQ2KissBuffs - Validate Writing to file

Update to verify we've actually written to the INI before updating the internal buff tracker so we don't say the INI has been updated when it actually hasn't been updated. I didn't clear CurrentPetBuffs OnZoned. Added. Removed ingame checks for OnZoned and ShutdownPlugin since it's not needed and could potentially prevent the file from being cleaned correctly. CleanBuffsFile checks for you to be in game before assigning a new ID, so it's not needed.