Fix recovering from Llama restart. Refactor connect/rpc/retry logic.

Change-Id: Idfbbfc3141cb9774d30ed1b1da4fe2cd9e511889
Reviewed-on: http://gerrit.ent.cloudera.com:8080/2685
Reviewed-by: Alex Behm <alex.behm@cloudera.com>
Tested-by: jenkins
Reviewed-on: http://gerrit.ent.cloudera.com:8080/2737