Respect decode404 flag and decode 404 response body

[dharmeshjogadia]

Fix the following decoder to decode 404 response body

• GsonDecoder

• JacksonJaxbJsonDecoder

• JacksonDecoder

• JacksonIteratorDecoder

• JAXBDecoder

• SAXDecoder

Fixes #809

[kdavisk6]

@dharmeshjogadia

Thank you for this PR, as you can see, there are number of issues. I suggest that you make sure that you are using the most recent version of master in your fork. Please either update your fork or rebase against master before continuing.

[dharmeshjogadia]

Hey @kdavisk6
I have updated the PR against the master and fixes the test as well.

[ugrepel]

Ehhh... after this fix, 404 is only processed into a null response if there is no body. If the 404 response does have a body, e.g. a typical HTML 404 page, or an application specific response which just happens not to be compatible to the expected type, then the result, in case of JaxbDecoder (others will be similar) is a DecodeException.

I would expect a null response, at least if the decode404 flag is set (which, in general, is ignored by the decoders affected by this PR).