Sort tasks displayed in the workflow

[idpaterson]

Spun off from #143, it would be useful in some cases to see tasks in a different order than they appear in the Wunderlist desktop app. This is already possible within the Due screen, but the implementation is a preference rather than a syntax that can be typed manually to sort as needed.

It is fairly simple to change the display order of tasks in any of the search or due screens. I could see this implemented as a Sort menu at the bottom of the results that displays a few properties you can sort by (created date, name, due date, etc). The menu would just autocomplete back to the search so you might end up with a command like wls shopping: -created showing the items in your shopping list with the most recently created tasks on top (+created for reverse order).

Unlike sorting in Wunderlist this would not permanently change the order of the tasks. Please 👍 if this would be useful to you.