Fix issue introduced by merge conflict
WINDUP-143: Make the navigationbar in freemarker reports dynamic
WINDUP-146: Expose generic services via GraphContext.getService(Model.class)
WINDUP-151: Use Collections.singletonList() in Variables.setSingletonVariable()
Merged WINDUP-186
WINDUP-148: Change commit behavior to (optionally) commit after every rule execution (in GraphSubSet)