Hadoop crypto codec framework and crypto codec implementations

For use cases that deal with sensitive data, we often need to encrypt data to be stored safely at rest. Hadoop common provides a codec framework for compression algorithms. We start here. However because encryption algorithms require some additional configuration and methods for key management, we introduce a crypto codec framework that builds on the compression codec framework. It cleanly distinguishes crypto algorithms from compression algorithms, but shares common interfaces between them where possible, and also carries extended interfaces where necessary to satisfy those needs. We also introduce a generic Key type, and supporting utility methods and classes, as a necessary abstraction for dealing with both Java crypto keys and PGP keys.

The task for this feature breaks into two parts:
1. The crypto codec framework that based on compression codec which can be shared by all crypto codec implementations.
2. The codec implementations such as AES and others.