Qt5 bindings for PackageKit, as an extension to the original PackageKit-Qt2 (actually using Qt4, don't be fooled 233)
$ cd PackageKit-Qt/
$ mkdir -p build
$ cd build
$ cmake ..
(but for Qt4 version please use cmake -DUSE_QT5=OFF .. here)
$ make
# make install
pkg-config --cflags --libs packagekit-qt5
A port PackageKit-0.8.8/lib/packagekit-qt2 to Qt version 5.2.x.