Allow EE Concurrency Utilities to be used without EE Component in context

I have seen cases of code trying to use the EE Concurrency Utilities (JSR-236) without an EE Component in the invocation context, and this currently results in a IllegalStateException.

This new feature removes such exception, and for these cases there is simply no invocation context setup before executing a task, in that sense it's no different then using a standard JDK Concurrency Utility.