test ::FFI::Callable->EXPORT

	modified:   t/ffi/callable.t
shorter delays in tests

	modified:   t/poex/zmq/pubsub.t
	modified:   t/poex/zmq/socket.t
POD

	modified:   lib/POEx/ZMQ/FFI/Context.pm
v0.005001

  - Add zmq_curve_keypair support via $context->generate_keypair

  - Support ZeroMQ-4.x SOVERSION change

  - Minor optimizations