Feature Request -- Reminder to Import if Generate is clicked with no data

[tonyrein]

If the user clicks "Generate ..." when there haven't been any VESTA reports imported, there should be feedback alerting that the import step needs to be done before any output files can be generated.

[tonyrein]

This could be done either via a tooltip (perhaps the Generate button could be grayed out until VESTA reports have been imported) or by a message box, or both.