Ready to merge, if tests are ok on travis.ci

I've added the extra link, together with robot test and unit tests. 

However I have some trouble with travis.ci.  If you look at the last tests, three tests for Plone 4.3 and 4.2 are failing. But each time other jobs are failing. I convinced the tests are working, maybe you can trigger a new test run in travis. As a contributor I cannot do this, only package owners can trigger a new test on travis. 

The last commit has a small change, I did that to trigger a new test run at travis. Unfortunately it didn't help. :)