I have made changes to the Import CSV dialog box; the new (proposed)
behaviour is as follows:
At first, the datePicker widget and OK button are disabled.
The datePicker is preset to today's date (no longer really
necessary, but the code is there).
User clicks 'choose a file' and the usual file browser appears.
If a file is selected, its creation date is stuffed into the
datePicker.
On return from the browser, the datePicker and OK buttons are re-
enabled.
User can modify the ride date, in case the file upload was not done
on ride day.
User clicks OK, the file is imported as before.