Created a new dialog, Edit Divecomputer, it will currently only lists
the divecomputers that are used on the xml file. I used the same method
that the gtk version used, but only 2 divecomputers got visualized in the
dirk dive data. I'll assume that it's correct and will fix it in the next
couple of commits.
Signed-off-by: Tomaz Canabrava <tcanabrava@kde.org>