Resources were being loaded 3 times (apptsummary, todosummary and in korganizer's kpart).

Now apptsummary and todosummary, instead of loading the resources, they just create korganizer's kpart (in case it doesn't exist yet), which loads the resources only once.

This also eliminates the "graphical bug" when switching to Summary, in which the agenda items disappeared right before the switch (because the second resource load closed the calendar).