lua.wire.active
active = wire.active(handle)
active = wire.active(thread)
If handle is nil then use wire.thread_handle
Check if this handle is an active thread, Eg the thread is running and should be dealing with memos.
returns false if not a thread or thread has halted or thread has been asked to halt.
returns true if thread exists and is running.
This function should be used in a running thread to check if that thread has been asked to halt.