Non-streaming ResponseWriters can't choose to not support gZip

[srstsavage]

This is probably low priority, but it doesn't seem like non-streaming ResponseWriters can choose to not support gZip encoding. This is because all responses are funneled through AbstractServiceResponseWriter (to enable streaming), which has this for its supportsGZip implementation:

@Override
public boolean supportsGZip(AbstractServiceResponse asr) {
    if (isStreaming(asr)) {
        return false;
    }
    return true;
}

In non-streaming cases, the supportsGZip method of the underlying ResponseWriter is never consulted (and the underlying ResponseWriter is only available during the write method).

Not sure how to solve this or even how important it is, but wanted to bring it up for discussion.