How do I get a YouTube video thumbnail from the YouTube API? Each YouTube video has 4 generated images. They are predictably formatted as follows:http://img.youtube.com/vi//0.jpg http://img.youtube.com/vi//1.jpg http://img.youtube.com/vi//2.jpg http://img.youtube.com/vi//3.jpgThe first one in the list is a full size image and others are thumbnail images. The default thumbnail image (ie. one of 1..