Since we are mixing properties and attributes in the atom
class it seems better just to standardize on the one that has
the most (attributes) and just mention that they are and should
always be immutable in the atom class documentation.
Depends-On: I18699fc64391445436537854a5e3723f4e89e961
Change-Id: Id03e4229b40b9da5c9a349ee00c13053a9eb75eb