Changeset 635 for trunk/web-app/images

• development version of samples page

-- improved handeling of samples
-- added warning page after clicking 'previous' in samples page

• fixed exceptions in deleting events
• added debug button to events page to reset revents
• changed events page to check for at least 1 sampling event instead of just 1 event (you need sampling events in order to have samples and groups later on)