Hook up the Download dialog

The download already worked, but we didn't display the new dives. This
introduces a new slot for MainWindow that updates what is displayed in
Subsurface after files were imported.

With this change we can successfully download ONCE - but when trying to
download a second dive the dialog doesn't appear to get refreshed the
right way - the OK button doesn't appear to work anymore (Cancel however
does).

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Enable Marble Google Sat lookup when run as a MacOSX app

Following Dirk's commit ae2c132, add support for custom google sat
data in a MacOSX app bundle

Signed-off-by: Henrik Brautaset Aronsen <subsurface@henrik.synth.no>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>