[tpcw-server] Add printStackTrace whenever an exception occurs in TPCW_servlets

  * Helps to understand what may be going on wrong...
[tpcw-server] Add infinispanPopulate.xml example file
Initial version of the 'cluster' application
[cluster] fix cluster configuration to run Infinispan backend

  * You may need to run with `-Djava.net.preferIPv4Stack=true` for multicast
    to work.
[cluster] Add another counter (IncrementOther)
Update README to mention 'cluster' app
Merge branch 'feature/cluster-app' into develop