ZMQ_LINGER does not work

see http://lists.zeromq.org/pipermail/zeromq-dev/2013-July/022199.html for
prosa.

Basically I suspect, that a sequence of:

1. sending a large message
2. close the sending socket

Does not respect the linger value of the socket, resulting in a lost message.

If the testcase https://zeromq.jira.com/secure/attachment/14602/zmq_test.cpp works for you it should fail with the assertion on line 140.