Divelogs.de: use qDebug() instead of fprintf()

Use qDebug() instead of fprintf(stderr, ...) in
prepare_dives_for_divelogs().

Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Divelogs.de: change the 'Apply' button to 'Done' for upload

Post downloading we have an 'Apply' button that can be clicked
to apply/merge the downloaded dives. When uploading we
rename the button to 'Done' and enable the button if the
upload was successful. The 'Cancel' button on the other hand
becomes disabled.

Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>