Fix urbi::initialize signature.
Fix urbi::initialize signature.

	* include/urbi/uobject.hh: Declare with the correct signature,
	  and a default value for the new argument.

aldebaran/urbi,urbiforge/urbi,aldebaran/urbi,urbiforge/urbi,urbiforge/urbi,urbiforge/urbi,aldebaran/urbi,aldebaran/urbi,aldebaran/urbi,urbiforge/urbi,urbiforge/urbi,aldebaran/urbi,urbiforge/urbi,urbiforge/urbi,aldebaran/urbi,urbiforge/urbi,aldebaran/urbi