Expose phys/uniq to the caller

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Let the name be dynamically allocated

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Update README

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>