Revert "Revert "Proper AsyncHttpClient runtime handling in SerializedSoc...

Hi Jeanfrancois

I can't reproduce the build failures we see on CloudBees.

I think my checkins are fine, after all. Could you have a look at the build test failures on Jenkins ? I tried hard to reproduce it locally with a wasync snapshot running on top of async-http-client 1.9.0-BETA19 against nettosphere 2.2.0. Both the ```noMessageLostTest()``` and the ```serializeFutureGetTest()``` are fine.

Thanks for having a look, Christian.