Apply Thrift SASL client/server framework for authentication/authorization/audit

For issue #397, enclosed please find the basic authentication/authorization/audit framework based on Thrift SASL implementation.  Nimbus integration and DRPC integration will be pushed as follow-up pull requests.

Authentication:
    - Support SASL authentication framework
    - Implemented SASL mechanisms: Anonymous, Kerberos, Digest
    - JAAS configuration

Authorization:
    - Enable plugins for Nimbus authorization against topology submission/killing/activation/deactivation/rebalance.
    - Plugin will have access to request context such as remote IP address, user name/principal etc.

Audit:
    - Simple log of operations performed by principals