Added the code to populate the tabs when a dive is selected.

So, this is what happens now:
Every tab should be populated from updateDiveInfo method, it will be
called whenever a new dive is selected
I'm already populating the 'notes' box to show how it can be done.
If you are unsure what's the name of anything, open the file maintab.ui on
the designer, click on the item and check its objectName, the access is
ui->objectName from here on.

Signed-off-by: Tomaz Canabrava <tcanabrava@kde.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Fill Dive Notes widget

Make sure we clear things out if no dive is selected.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>