use lazy vars and assigned closures instead of iVars

Hi,
I studied the AppDelegate and tried to figure out how it works. I saw that it uses iVars for the stored core data objects. Because swift avoids the use of iVars, I thought there should be maybe a better way to store the objects ;). The code for a core data supported app-template created by XCode6 beta6 uses lazy vars instead....
Cheers
Daniel