on Anne's karmic koala, gtk_events_pending() is much more often true than on my machi...

on Anne's karmic koala, gtk_events_pending() is much more often true than on my machine, while loading for each photo loading is interrupted and sometimes after a while, there is no progress anymore because of every interrupting; I don't know why it happens and I think it should not (WM interaction?), but I don't know how to fix that with the previous approach, so as it was needed to change the approach (instead of canceling loads, just interrupt them, but continue them after) here is a new more efficient approach which would workaround the aforementioned problem