* make DataEngine take a QObject in the connect, making DataVisualization somewhere superfluous. unless it ends up doing something useful soon, DataVisualization as a class will be going away.
svn path=/trunk/KDE/kdebase/workspace/plasma/lib/; revision=667167
* move DataSource::Data to DataEngine::Data; this means consumers of DataEngine have no need to know about DataSource as a class
svn path=/trunk/KDE/kdebase/workspace/plasma/lib/; revision=666756
* queue updates so that multiple calls to setData don't result in a storm of updated signals
* some API cleanups, e.g. connect -> connectSource
* provide and install a ServiceType .desktop; this adds the X-EngineName QString symbol. maybe that's too generic.
svn path=/trunk/KDE/kdebase/workspace/plasma/lib/; revision=666241