Feature: allow tuple inequalities in symmetry breaking

[MaxOstrowski]

Feature request: Add support for tuples:
foo(X) :- room(X, P1, V1), room(X, P2, V2), (P1,V1) != (P2,V2).
This means "derive head if at least one of the elements is different". This is different to P1 != P2, V1 != V2. It is an or, not an and. This could still be translated to:
(P1,V1) < (P2,V2) as long as all variables come from the same place from the same predicate.