Remove component-managed from the spec
We should remove component-managed from the spec, because this function is duplicate of what a user would get by supplying a ManagedThreadFactory to a Java SE executor service.
Regarding the sentence "If the threads are pooled, the overhead of reusing a thread disappears since the context does not have to change the thread's context." - This statement isn't entirely accurate. Think of security context, where different users are running the same component. It would be an error to keep reusing the context of user1 on pooled threads for user2 and user3 who are also using the component. The the security context will be all wrong. This is another reason why we want to get rid of Component-Managed Executor. If we instead let it be the component's responsibility to get this behavior by supplying a ManagedThreadFactory to a Java SE executor service, then it will be clear to the component exactly what they're doing.