Import ui

Adding the ability to import previously exported data + some UI for it.
I added this since the data import is a distinct operation that you rarely perform, and once it's done you want to see the result of it immediately. My gut feeling tells me that the number of people that want to change another setting after importing their data, versus the number of people that want to check out the imported data is about a 0.01 99.99 split :)

It is not optimal that the import operation is in settings at all, but that the least awkward place I could hide it.