Do not use a const ref on non-mandatory attributes.
Do not use a const ref on non-mandatory attributes.

Non-mandatory attributes should not be set or constructed using a
const ref, as they may not be present.

	* dev/ast.py: Use "type" instead of "const type&" for
	non-mandatory non-pointer attributes.

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