Deprecated `DifferentialActionModelActuated` and `DifferentialActionDataActuated` classes

These are legacy classes that they're not used any more. @nmansard noticed in this PR !96 (merged).

changed milestone to %Towards python version 1.0

mentioned in merge request !96 (merged)

mentioned in issue #79 (closed)

assigned to @nmansard

added on-going label

mentioned in merge request !127 (closed)

Solved by !127 (closed)

closed

mentioned in merge request !128 (merged)