Fix PAI::createActionPlan() when concept node plan_selected_demand_goal not exist

It made the assumption that a concept node plan_selected_demand_goal
exit, this is apprently created by OpenPsi. PAI should not have that
kind of depence on OpenPsi, ultimately that logging code should be
moved out of that method.
Remove comment about OpenPsi PAI dependence as ActionPlan takes a demand in argument
Some minor PET -> AVATAR fix