renaming a file, the map of file names to collection list items wasn't updated,
which caused duplicate entries to appear when the History list added an entry
when you play the newly-renamed file.

Although disabling the KDirWatch doesn't appear to be actually necessary to fix
the bug, I'm leaving that part in because I think that once 85534 is fixed it
will expose the bug again.

svn path=/trunk/kdemultimedia/juk/; revision=332434