Fixes pause/resume support on PipeDescriptor and possibly other connection types. See #245 for more info.
EventMachine relies on the fact that when close(fd) is called that the fd is removed from any epoll event queues. However, this is not *always* the behavior of close(fd) See man 4 epoll Q6/A6 and then consider what happens when using pipes with eventmachine. (As is often done when communicating with a subprocess) The pipes end up looking like: ls -l /proc/<pid>/fd ... lr-x------ 1 root root 64 2011-08-19 21:31 3 -> pipe: l-wx------ 1 root root 64 2011-08-19 21:31 4 -> pipe: This meets the critera from man 4 epoll Q6/A4 for not removing fds from epoll event queues until all fds that reference the underlying file have been removed. If the EventableDescriptor associated with fd 3 is deleted, its dtor will call EventableDescriptor::Close(), which will call ::close(int fd). However, unless the EventableDescriptor associated with fd 4 is also deleted before the next call to epoll_wait, events may fire for fd 3 that were registered with an already deleted EventableDescriptor. Therefore, it is necessary to notify EventMachine that when an EventableDescriptor is closing so that it can remove it from the event loop.
…ter a completed state is entered.