Previously, KNSCore only signalled errors using string messages, which were useful for fault finding, but not useful when attempting to handle errors during general operation. This patch adds a signal which is fired at the same time as some error messages, and which provides error condition information which is useful in a programmatical fashion.
This patch would allow https://bugs.kde.org/show_bug.cgi?id=395937 to be fixed in a non-hackish fashion.