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

Rename ContentTypeBasedKey to HttpSerializationContext.

Added HttpHeaders implementations for all clients.

Merge branch 'master' of https://github.com/Netflix/ribbon into 1.x

Conflicts:
	gradle.properties
	ribbon-core/src/main/java/com/netflix/client/config/CommonClientConfigKey.java

Reopen closed but not merged pull request https://github.com/Netflix/ribbon/pull/64

Add client port config override

- 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

add helper method to get or create a client with a custom config class

This reverts commit 5f62ec1f.

Fix Issue #61

add hook for custom ssl factory and AcceptAllSocketFactory implementation

Make sure NamedConnectionPool instances register with Servo with unique names.