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

Hi Jeanfrancois

I can't reproduce the test failures we see on CloudBees.

I think my checkins are fine, after all. Could you have a look at the 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. But locally both the ```noMessageLostTest()``` and the ```serializeFutureGetTest()``` are successful.

Thanks for having a look, Christian.

ps: now ran a local build in a not-locked-down environment, i.e. at home where I do have Snapshot repository access. Downloaded zip of this repository and executed a full maven build - all tests pass. I really don't understand what jenkins is building against and/or why some tests fail there since a few weeks.