1187 d_USBMass1 auto-sync redundant playlist copies [#5827]

[chrisjj]

Every time I auto-sync my d_USBMass1.dll device, MM copies all* of the 160-odd library playlists, despite that none of them have changed.

(My device is a HD folder mapped to drive letter.)

EDIT: * all that is except the only one that is empty.

EDIT: Persists on 1256.

EDIT: Persists on 1708.

[chrisjj]

Tracked at http://www.ventismedia.com/mantis/view.php?id=5827