dive sites, edit undo, and the major steps towards 4.9

[Salvador Cuñat]

Good night.

On Sat, Apr 13, 2019 at 09:27:30AM -0700, Dirk Hohndel wrote:
> 
> There are a couple of exceptions: tanks, weights, and editing the dive points of a manually added dives by dragging things around in the profile. Those still use the old accept / reject concept (which creates a rather inconsistent user experience right now - but it seemed the right time to merge this massive PR, even with a couple of items missing). This part could use serious testing, feedback and bug reports, and of course updates to the documentation.
> 
At current master 8d3982c.
In a first try, the only thing I've noticed to fail is autocompletion
in "Dive Master", "Buddy" and "Tags", while it works fine in "suit"
and in "Divesite".

The new divesite management looks superb. Very good work Berthold.

The lack of the accept/reject buttons is weird, but mainly because I'm
used to it. The weirdness will disappear with use, and new users will
never miss it. With the undo feature it's a big step too.

Best regards.

Salva.