[KNotification] method sendEvent() is not called.
If you compile KDE from source, you should be able to specify the “prefix” where to install it, most commons are /usr/local, /usr/, or somewhere in your home directory if you don’t want to have it system-wide (especially with KDE unstable branch).
In /usr/local, which is your prefix, there are main configuration files. They contain the basic options and configuration for each application. When you first start a KDE application, configuration files are copied from your prefix into your home directory, so that you can customize them without touching the original files in /usr/local (also because you normal user don’t have enough permissions). You home directory should be $HOME/.kde or $HOME/.kde4. The next time you start the same application, configuration are read both from your own config file in .kde or .kde4, and merged with other option in the “global” configuration file (in /usr/local).
To access data in a configuration file (I’m talking about config file of your application, which you implemented) you have to use KConfig, KConfigGroup and other classes in your application. Also, you don’t need to specify where to put your configuration file, KDE will create it in your home directory (again, .kde or .kde4), simply create a KConfig or KConfigGroup object, and read or write entry into your config file.