Configuration window was too small, did not show any of the fields.
Set previously configured resources and period as initial values in config dialog
find row to insert into, instead of overwriting first x rows. still very slow.
Only get row by searching for the first row, after that assume right order of incoming json. Much faster now.
Remove test function
In-code comments for better understanding
Merge pull request #6 from tiefpunkt/master

Fixed configuration window, improved data insertion into spreadsheet