This introduces filtering which is applied onto any entry before handing it to the framework user. Filters can be set either via knsrc files, or through the Engine API. A default filter is set to ensure that if the server suggests certain items should not be shown, those entries will be hidden from the user (this is already supported by the KDE Store, and this ensures we support that in our client side).
It further adds a test tool to more easily perform testing on KNewStuff's functionality (originally based on the old knewstuff2 tester, but now with more functionality, and better visual feedback).
As it depends on D6512, this patch should consequently not be merged before that one is.