Merge pull request #197 from tbak/2.x

2.x composite interest index + ribbon in eureka-client + a few other updates
Merge pull request #199 from tbak/2.x

Remove MessageBrokerServer and MessageBrokerBuilder abstractions
moving EurekaRegistry instantiation outside of EurekaService on the client
Merge pull request #200 from qiangdavidliu/2.x

moving EurekaRegistry instantiation outside of EurekaService on the client
Add EmbeddedEurekaCluster, to run full cluster in one JVM.
Add read server - WIP + refactor the code to be more guice friendly.