Add per-cache coordinator.

We trying to use Infinispan for our cluster. We have two types of nodes in cluster. "Type 1" nodes use all set of caches defined in system, but "Type 2" nodes uses only small subset of caches. For each cache on each node we have job, that fetch data from external store and put that data in the cache. We need this job to be executed only in one node from whole cluster and is natural to test if node is cache coordinator and execute job only if it is. In current implementation it's possible to determinate only cluster coordinator. But when node of "Type 2" becomes coordinator it is impossible to update some caches, because they are not defined in this node. It would be fine to declare not only oldest node in cluster as cluster coordinator but oldest node containing cache as this concrete cache coordinator.