depend on perl-5.16

OK, admittedly I don't actually know why tests hang on <=5.14.x, but I don't
actually have any of those left myself so punting ;-)

	modified:   dist.ini
skip probably unnecessary sleep in async test

	modified:   t/poex/zmq/socket.t
skip unnecessary ArrayObj coercion

	modified:   lib/POEx/ZMQ/Socket.pm
expand FFI::Socket tests

	modified:   t/ffi/socket.t
POD fixes

	modified:   lib/POEx/ZMQ/FFI/Socket.pm
Types improvements; ZMQSocket[$type], use ZMQSocket for async socks

	modified:   dist.ini
	modified:   lib/POEx/ZMQ/Socket.pm
	modified:   lib/POEx/ZMQ/Types.pm
	new file:   t/types.t