[8.0] Clustering testsuite on Windows mega fix 

The problem is that Managed*DeployableContainer kills the managed server instead of regular shutdown in stop() on Windows. ARQ's stop is supposed to shutdown the server 'nicely', for abrupt termination there is jvmKill(). 

This was probably implemented like this incorrectly assuming that on windows, the process is sent SIGTERM like on *NIX-based OSes but there is no such thing on windows and the process is terminated immediately.

This shows up only in clustered tests, compared to other tests which dont rely on the shutdown sequence to be completed, but clustering testsuite relies on shutdown to disconnect the channel and leave the cluster without FD having to kick in.

https://issues.jboss.org/browse/AS7-6620