great progress on dive site handling

[Dirk Hohndel]

Thanks to Tomaz for continuing to work on this.

The poor guy did two complete implementations that we ended up rejecting,
now he's started the third rewrite. And I think this one is promising.
Davide, this is not a departure from what you suggested but a small
addition - something that was doable in a limited amount of time and that
gives us back code that works - so it's now again possible to add and
modifiy dive sites.

This implementation allows you to type in the location box on the notes
panel. It will autocomplete to known sites and add a new site if an
unknown name is entered.

The edit button then opens a "quick edit popup" that is intended to
quickly edit / enter data. This is done as a popup to show that this is
just editing the site at which this dive happened.

The full dive site management screen will then no longer be used for just
the "edit this dive" mode but instead for more general dive site
management - but that code doesn't exist, yet.

I tested this quite a bit and for me it worked in all the scenarios I
tried. I'd really appreciate if people could play with this. Miika, you
selflessly are collecing data for us - so you have good reasons to want to
edit dive sites right now. Please give this a try and tell us if it works
as expected.

I added code that I believe made the trip location edit work in a sane way
again (that had been broken for quite a while).

And I made another attempt to tackle the insanity of zoom on the Globe.

So quite a few fixes, lots of things to test. Please give the latest
master a try (I'll trigger daily builds in a moment).

/D