We had this test with tree manifest only because the tests were broken and we
were fixing them and maintaing two different cases of broken tests was bit hard.
Now that things work fine, let's add the flat manifest case.
The test shows that things work fine in both cases.
I know that you're just copying this from other test, but I wonder why we didn't just use {rev} instead of {node|short} so we didn't have to glob it out. It makes more sense to fix that in all the tests after this series, of course.