another version hessian2 support

[wbpcode]

A helpless fact is that there are two different versions of hessian2. One is the version that the dubbo used. See http://hessian.caucho.com/doc/hessian-serialization.html.

Another is the version the sofa used. See https://www.caucho.com/resin-3.1/doc/hessian-2.0-spec.xtp

They are incompatible. :(

Will the community accepts the related implementation of the another version? cc @zyfjeff

[zyfjeff]

These two are not the same thing, the former is the definition of a Hessian Web Service, and the latter is the serialization of the base type of Hessian

[wbpcode]

Sorry, I pasted error link in the description. Updated. :)

[zyfjeff]

Obviously, sofa uses the draft version of the hessian2 spec, which is not officially supported, and we should not deviate from the official spec for a long time, sofa should be compatible with the official spec

[wbpcode]

Ideally, yeah. But, I think it's hard (and maybe impossible?) for sofa to do this update. Because this require all sofa services in the cluster to update the codec lib version at same time. These is no any compatibility between these two versions. orz.