KFilterModel and assorted issues

[Adam Treat]

Harry, is it ok to go ahead and delete KFilterModel now that we have 
QSortFilterProxyModel?  I assume that this obsoletes the former.

Roberto, Harry, I'd appreciate it if you guys and any of the Troll's 
responsible for the model/view stuff could have a look at the 
KDevCodeAggregate/KDevCodeProxy stuff I committed.  It seems to work, but I 
am not sure I have all the signals and inter model interaction figured out 
correctly.

Cheers,

Adam