Allow generation of the empty symbol
Allow generation of the empty symbol

	* src/object/symbols-generate.pl: Allow generation of the empty symbol,
	"symbol_", a.k.a. "SYMBOL()".

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