Continue to send invoice reminders until paid

You now are able to repeat your invoice payment reminders after the due date has passed to ensure that your clients continue to be notified of any outstanding balances owed.

Even better, these reminder settings no longer need to be set on new projects: the "App defaults" page has a configurable reminder setting to apply for the first invoice on any project. This default will only be set on the first invoice for a project. All subsequent ones will use whatever the previous invoice's reminder settings were.