Fixed https://intevation.de/roundup/kolab/issue758: when accepting an invitation, and korganizer isn't running (or not loaded in kontact), start korganizer. In the kontact case, it will load it in the background without bringing it to front, thanks to the new load() dcop method in the KUniqueAppHandler. The point in all this is to show the dialog immediately, not when starting korganizer the next day.

Use this technique in certificatewizardimpl.cpp too for consistency (and to
remove a wrong comment of mine there).

svn path=/trunk/KDE/kdepim/; revision=418506