Add ability in Hadoop servers (Namenode, JobTracker, Datanode ) to support multiple QOP (Authentication , Privacy) simultaneously

Add ability in Hadoop servers (Namenode, JobTracker Datanode ) to support multiple QOP (Authentication , Privacy) simlutaneously

Hadoop Servers currently support only one QOP(quality of protection)for the whole cluster.
We want Hadoop servers to support multiple QOP at the same time.
The logic used to determine the QOP should be pluggable.
This will enable hadoop servers to communicate with different types of clients with different QOP.

A sample usecase:
Let each Hadoop server support two QOP .
1. Authentication
2. Privacy (Privacy includes Authentication) .
The Hadoop servers and internal clients require to do Authentication only without incurring cost of encryption. External clients use Privacy.

An ip-whitelist logic to determine the QOP is provided and used as the default QOP resolution logic.