Since this is now in C++, we don't have to use our crazy
TABLE_* macros.
This contains a logic change: the dives associated to a
dive site are now unsorted.
The old code was subtly buggy: dives were added in a sorted
manner, but when the dive was edited the list was not
resorted. Very unlikely that this leads to a serious
problem, still not good.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>