When showing the "empty-state", the profile toolbar was
disabled. This was done via a "reverse" signal from the
profile to the MainWindow. Instead control the toolbar
in the MainWindow directly. Break out the plot-dive
functionality into a member function and there test
whether a dive is shown or not.
The signal makes no sense in the context of mobile
or printing.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
8939b6a99b