Upgrading to HTTP/2 draft 14 HTTP/1.x message flow

Motivation:

HTTP/2 draft 14 came out a couple of weeks ago and we need to keep up
with the spec.

Modifications:

-Allow informational type messages to be sent up the pipeline immediatley.
-Corrections to HttpObject comparitors to support test cases
-New test cases to support sending headers immediatley
-Bug fixes cleaned up to ensure the message flow is terminated properly

Result:
Netty HTTP/2 to HTTP/1.x translation layer will support the HTTP/2 draft message flow.
@nmittler - Here is where the lack of decompression is.  I would like to provide hooks into `DefaultFrameReader` so that before [this line: DefaultHttp2FrameReader.java#L382](https://github.com/netty/netty/blob/master/codec-http2/src/main/java/io/netty/handler/codec/http2/DefaultHttp2FrameReader.java#L382) a `ByteToMessageDecoder` can be used to decode the data before passing to the observer.  I was thinking along the lines of providing an interface to set a `ByteToMessageDecoder` (which would be done when headers are read/interpreted). Providing this interface allows flexibility to determine which implementation is to be used for decoding (the HTTP/2 layer could also exercise this interface by analyzing headers).  I would like to mirror the relationship `HttpContentDecoder` has with the `ChannelPipeline` in that by default nothing is done automatically, but if you specify an alternative class you will get decompression. What are your thoughts?