[DROOLS-247] Property reactivity does not work with positional/unification constraints
[DROOLS-64] [DROOLS-113] Cleanup applyTrait method, support imperfect don
[DROOLS-248] Declared Traits do not inherit fields if multiple inheritance is used
[DROOLS-250] avoid NPE in MVELConstraint
[DROOLS-244] Sliding windows working incorrectly when timestamp attribute is defined