Fix FFI::Role::ErrorChecking; err_handler is now public

	modified:   lib/POEx/ZMQ/FFI/Role/ErrorChecking.pm
FFI::Socket->soname should be buildable from ->context

	modified:   lib/POEx/ZMQ/FFI/Socket.pm
POD

	modified:   lib/POEx/ZMQ/FFI/Role/ErrorChecking.pm
	modified:   lib/POEx/ZMQ/FFI/Socket.pm