Ticked 2

Apple reminded me that, after three years, I need to update or they'll take the app down! This update moves the data model over to Core Data with Cloudkit, meaning: Pro: simpler, more reliable syncing between same-user devices using Apple boilerplate code. Con: sharing between users has been dropped (at least for now). It's technically possible, so if there is demand I will look at incorporating it in a future update (in less than three years!). Feel free to email mike@mclay.dev to share your thoughts. I likely will not respond, but will evaluate demand accordingly. Thank you, and I hope Ticked continues to be useful for you well into the future :)