Clustering : Programmatic Cluster configuration

Cluster members are defined statically in akka.conf. New cluster configurations requires changing this file on each system and restarting the controllers.

Update to provide a way to programmatically configure a cluster including options that are currently part of akka.conf and potentially others we want to support. In general:

• Controller's address (IP/Hostname)
• Other cluster member's addresses (IP/Hostname) including Akka "seed nodes"
• Akka-specific config (ActorSystem config, logging, serializer, etc.)

Provide a REST interface to create/destroy a team?