[SUGGESTION] If action has the same predicate in both positive and negative effects, remove the predicate from negative effects

[o-fir]

Assume we have this action:

(:action do_grind
		:parameters (?part_x - part ?do_grind_oldsurface - surface)
		:precondition 
			(and
				(surface_condition ?part_x ?do_grind_oldsurface)
			)
		:effect
			(and
				(not (surface_condition ?part_x ?do_grind_oldsurface))
				(surface_condition ?part_x verysmooth)
			)
	)

If we have a grounded action (do_grind p0 verysmooth), PDDL4J grounds it in such a way that (surface_condition p0 verysmooth) is in both positive and negative effect bitvectors. I think it would be safer if it only appeared in positive bitvector, even though it would restrict cases where someone wants to prioritize negative predicates.