Fix #147 Implement CallBehaviorAction in Activity diagram

Add CallBehaviorAction mapping as ExecutableNode conditional style.
Decorators were also defined to add a small icon according if the
behavior associated to a call behavior action is an activity or a
state machine.
Navigation tools were also implemented to navigate directly or
create the corresponding activity/statemachine associated to the
call behavior action.
Properties view was also improved by adding EEF properties for the
CallBehaviorAction, StateMAchine, Region, Interaction, OpaqueBehavior
and Activity.