Partitioners that cache state should take topic into account

[jkorab]

Not all topics will have the same number of partitions. Using an old computed hash that points to a non-existent partition will cause an explosion.

To test, set up a 2 topics with [2,1] partitions, [1,1] producers, [2, 2] consumers and use the sticky partitioner. Should start throwing exceptions from the single-partition producer.