Some refactoring for IMS QTI 2.1 exporting
Some refactoring for IMS QTI 2.1 exporting

rogervaas/vish,rogervaas/vish,ging/vish_orange,rogervaas/vish,agordillo/vish,agordillo/vish,ging/vish_orange,ging/vish,ging/vish,suec78/vish_storyrobin,suec78/vish_storyrobin,suec78/vish_storyrobin,rogervaas/vish,ging/vish,agordillo/vish,ging/vish_orange,agordillo/vish,ging/vish,suec78/vish_storyrobin,ging/vish,ging/vish_orange,ging/vish_orange