Add a send timeout in expect_bounce_fail() so tests for authentication
failures don't block.
Set an alarm(60) in setup_test_environment() when not on windows so tests
will not block too long if they go wrong.
Merge pull request #1046 from mrvn/pull-testutil-set-alarm

Set an alarm(60) in setup_test_environment() when not on windows so test...
Merge pull request #1047 from mrvn/pull-testutil-expect_bounce_fail-send-timeout

Add a send timeout in expect_bounce_fail()
Problem: security tests block on zmq_send

The expect_bounce_fail () helper assumed that messages could always
be sent. However in some cases zmq_send() blocks, due to there not
being any outgoing pipe. This changed in 77f5f7, where previously
there would be a pipe that kept trying to reconnect forever.

Solution: use a send timeout and check for EAGAIN if sending failed.