The dive selection was initialized during data-reset. However,
this emitted a signal before all data-reset routines were run.
Ultimately, this led to access-after-free in the statistics code.
Instead, move the select_newest_visible_dive() signal from the
divelist-model to the process_loaded_dives() function. There
is no point in initializing the selection if the dive data
is cleared after all.
This change broke closing of the log, because the UI-selection
was not reset. Therefore, when clearing the data, clear the
selection before proceeding with clearing.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>