Flexible tasks and Scheduled tasks UI need tweaks

Flex tasks should be: Months/Days/Weeks. They begin to become stale at midnight. We don't need minute granularity!

Scheduled tasks:
- minutes need to be checkboxes, 0, 15, 30, 45
- Day of the week should be checkboxes too
- Should be able to have things trigger every N days/weeks/months
- Add a switch for the interval, that toggles it to be before or after the due date