Added classes to handle the completion of dive editions, the
classes are BuddyCompletionModel, DiveMasterCompletionModel,
SuitCompletionModel and LocationCompletionModel, thanks to
plain old C macros, code got really small. and I hope the
logic is better than the Gtk version. :)
Now next step is to integrate it to the Ui. shouldn't be hard.
Signed-off-by: Tomaz Canabrava <tcanabrava@kde.org>