Test tweaks.

	new file:   .gitignore
	modified:   t/02_class/02_publisher_subscriber.t
Defer object destruction; passes tests more reliably.

	modified:   lib/POEx/ZMQ3/Role/Sockets.pm
Defer cleanup steps a bit more, set ZMQ_LINGER earlier.

	modified:   lib/POEx/ZMQ3/Role/Sockets.pm