How to use the new motion tracking in kdenlive?

I've installed the latest updates from sunab's kdenlive-svn ppa. As I've read in j-b-m's blog that there is now a new motion tracker feature included I would like to know how to access and use it. I have to admit that while looking around, so far I was unable to find out where it is hidden and how to access it. From the blog entry I could not deduce how to use it... :(

Any help?


I am also interested in this feature but can't find a solution.