some changes to the stats tab

[Dirk Hohndel]

Since the stats tab apparently caused confusion (especially with only one
dive selected), I made a few changes and added more tooltips. I think this
is much clearer now, but unfortunately this added a few new strings that
need to be translated.

I don't worry so much about Beta 1, but just keep this in mind if you are
one of the people helping to get things translated for the 4.3 release.

I just kicked of a new set of Windows builds which should be on the server
shortly (-569). Assuming I don't stumble into anything really annoying
over the next hour or two I hope this can finally become the long delayed
Beta 1.


/D