ISPN-263 Handle cluster partitions

* add logic to handle split brains
* when a split brain happens, the consistent hash of the cache freezes till the nodes that disapeared ressurect
* the cluster enters degraded mode, i.e. only servers data that hasn't been affected by the split brain
ISPN-4420 Allow configuring keepalive for hotrod connections
- implemented functionality to determine multiple successive failures.
don't allow for stale data in an resurrected member.
ISPN-263 Handle cluster partitions
 - enhanced the test suite with various nodes failures
ISPN-263 Handle cluster partitions
 - allow configuration through XML
ISPN-263 Handle cluster partitions

* fixed test suite