Dictionary.getWithDefault: Add an optional arg to insert the default.
Dictionary.getWithDefault: Add an optional arg to insert the default.

	* share/urbi/dictionary.u: Here.

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