Implemented redirect using Observable APIs. Added JUnit tests. Retrofit serialization framework to RestClient.

- Added ribbon-rxnetty module for asynchronous HTTP communication based on Netty and RxJava
- IClientConfig and IClientConfigKey supports typed property
- Updates to serialization factory and serializer interfaces (replaced Guava TypeToken with TypeDef in the interfaces)
- Updates to HttpRequest and HttpResponse interfaces with addition of HttpHeaders

In JUnit, make sure connection pool size is equal to concurrency level to avoid timeout from connection pool.

Add internal buffering to any unconsumed data by the decoder so that decoder does not need to repeat the boilerplate code to buffer unconsumed data. Changing the JUnit tests and examples correspondingly.

Add more locks to AsyncBackupRequestExecutor to make it run consistently across implementations.

Added Http async interfaces to hide generic types for convenience. Added more examples. Execution with back up requests factored out to a standalone class.

Rename test. Added getExecutedURI() to query the host where the actual execution happens for parallel execution with back up requests.

Added more API to query executeWithBackupRequests() results. Make sure cancel works correctly. Close the consumer as part of response.close().

Added LoadBalancerErrorHandler and provided default implementation and one for httpasyncclient. Move HttpResponse class to desired package.

Added examples sub project. Changed the serializer interface to use OutputStream. Make Response and AsyncClient extends from Closeable.

Code refactoring to simplify the async and callback interfaces. Implemented returning future from load balancing async client.

Support for async communication using Apache's HttpAsyncClient. Added streaming interface. Added support for Observable.