shell32/shflder_unixfs: Use shell kind ITEMIDLISTs

[Michael Jung]

This silences some ERROR messages when browsing in the namespace extension and 
allows to apply shell32's helper functions.

Changelog:
	Use the shell32 typical binary format for ITEMIDLISTs.

Bye,
-- 
Michael Jung
mjung(a)iss.tu-darmstadt.de