Factor the generation of symbols.
Factor the generation of symbols.

	* src/parser/utoken.l (RETURN_SOME_SYMBOL): New.
	Use it to have a unique place that creates symbols.

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