Anchor bottom of the dive ruler editor ro items on the DivePlanner

This patch is a crude attempt to 'anchor' the bottom of the Dive
ruler editor ( the new graphics ) to the bottom of the scene.
since QGraphicsView doesn't have a good way to modify the origin
point of an item, I'v just shifted all other items up a bit, this
way the 0,0 point is in the bottom of the drawing and I can safely
move it around, making it bottom-anchorable. :D

Signed-off-by: Tomaz Canabrava <tcanabrava@kde.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Make it posible to renumber dives.

If the user doubleclicks on the number of the dive in the dive list,
this will present to him a dialog to change that number. Pressing enter
will renumber the dive if there's no dive with the same number already.

Fixes #288

Signed-off-by: Tomaz Canabrava <tcanabrava@kde.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Do not let the dive have the 0 value.

The number 0 means "this dive has not been numbered". So manually
assigning this seems wrong.

Signed-off-by: Tomaz Canabrava <tcanabrava@kde.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Change the order of the increase / decrease buttons on the planner.

Change the order of the increase / decrease depth button on the planner
since 'bottom' means increase depth and 'top' means decrease. Sorry
I'm too undiver currently :)

See #269

Signed-off-by: Tomaz Canabrava <tcanabrava@kde.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Quick hack to make the dive add icons smaller

This is about the right size, but the scaling pixelates the icons. So this
is not really a fix, just a hack.

See #269

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