make GPS coordinates autofilling really work

Move the gpsHasChanged() call on selected dive when coordinates have
changed *before* autofilling, otherwise it erases the autofilled values.

Also update displayed_dive when autofilling, otherwise values are stored
but not displayed immediately after saving.

Signed-off-by: Gaetan Bisson <bisson@archlinux.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Fix picture loading

Signed vs unsigned comparisons are such a pain. Since we want offsets to
be +/- 30 minutes around the dive we need to allow negative offsets - but
duration_t was defined as uint32_t.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
replot() needs to really force a replot

So let's set forceReplot to true to make sure that happens.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Picture handling: make sure pictures are shown after they were added

We need to first replot() to get displayed_dive updated, then call
refreshDisplay() so the picture model gets repopulated which triggers the
pictures to show up.

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