Recognize Spacelift threads from all others regarding of a thread name

It is hard to distinguish between Spacelift threads and all other threads in the system.

ExecutorServiceImpl creates executor services via Executors.newCachedThreadPool and Executors.newScheduledThreadPool(1) which are naming threads like "pool-1-thread-_number" and it is hard to make a difference what is Spacelift related and what is not in tools like jvisualvm or jconsole.