Add console log to indicate the node is ready to accept requests

Depending on whether a cluster is initialized the first time, or a node is restarted, the last message on the console varies. In either case, there's no indication that the cluster/node is ready to accept requests.

For example, when I create a new Cassandra Docker container locally:

$ docker run --name cas -p 9042:9042 -p 9091:9091 -e CASSANDRA_DC=dev cassandra
...
INFO  [OptionalTasks:1] 2019-06-11 23:31:35,527 CassandraRoleManager.java:356 - Created default superuser role 'cassandra'

After shutting it down (CTRL + C), and restarting:

$ docker start cas
...
INFO  [main] 2019-06-11 23:32:57,980 CassandraDaemon.java:556 - Not starting RPC server as requested. Use JMX (StorageService->startRPCServer()) or nodetool (enablethrift) to start it

In either of the above cases, how is a regular user, whose full time job is not working with Cassandra, expected to know whether the server is ready? We have a new member in the team who previously was an iOS developer. He left the server running overnight, assuming the node hadn't finished initialization; the next morning, the last message was still "Created default superuser role 'cassandra'".

Please add a simple log statement with basic information like node IPs in the cluster indicating the node is ready. For example, this is what Spring Boot does:

2019-06-11 16:37:28.295  INFO [my-app,,,] 17392 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 11900 (http) with context path ''
2019-06-11 16:37:28.299  INFO [my-app,,,] 17392 --- [           main] mypackage.MyApp   : Started MyApp in 5.279 seconds (JVM running for 5.916)