Qt4 duplicates SD items

When a SD plugin creates items before it returns from pf_open, the Qt4 dialog shows those items twice in the playlist. This affects both categories and actual items.

This cannot be fixed at the SD plugins-level, since those plugins do not know "when" to start other than from pf_open.

This affects the udev plugin quite badly.

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information