Avoid marble widget resize when switching dives

The "no dive location" message box was displayed above the marble
widget, which made the layout splitter move horizontally.

Made the message box as an overlay on the map instead.

Signed-off-by: Henrik Brautaset Aronsen <subsurface@henrik.synth.no>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Correct the code to enter dive locations

The existing code converted the lat/lon to int before multiplying with
1,000,000 (in order to create udeg). Oops.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Don't show the compass

North is always up anyway.  At least that's the way we've done it so far.

Signed-off-by: Henrik Brautaset Aronsen <subsurface@henrik.synth.no>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
If we disable the compass, we don't need to place it, either

Just completing commit f1a4edc5497d ("Don't show the compass").

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Fix GPS coordinates rounding.

Better round the coordinates.

Signed-off-by: Sergey Starosek <sergey.starosek@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>