Dolphin is a file manager, and shouldn't be concerned with non-file
    resources like notes, contacts and other stuff.
    
    Use FileQuery instead of Query.
    
    This also results in a faster queries. With File Queries Nepomuk can
    perform some internal optimizations.

PS: I'd like to get this into 4.9.1, so a fast review would be nice. Also, do we cherry pick or merge KDE/4.9 into master?