Update to oasis 0.3.0 for OCaml 4.x compatibility
Merge pull request #5 from hcarty/ocaml-4.00.0-compatibility

Update to oasis 0.3.0 for OCaml 4.x compatibility
Fix typo in caml_zmq_get_events

Use event_type instead of event.
Events is a value received from zmq_getsockopt and it may be
arbitrary. Event_type is calculated value, corresponding to event type
in ZMQ.ml .
Current implementation only works because ZMQ_POLLIN=1 and ZMQ_POLLOUT=2,
so event and event_type equal each other.
Merge pull request #6 from little-arhat/fix-get-events

Fix typo in caml_zmq_get_events