test: refactor to eliminate flaky test

This retains the key elements of test-child-process-fork-getconnections
(forks a child process, sends a bunch of sockets, uses getConnections()
to enumerate them) but contains some code to work around an apparent
intermittent bug that occurs on OS X where a socket seems to close
itself unexpectedly.

nodejs#2610 was opened for the bug that
was causing the problem in the first place.

PR-URL: nodejs#2609
Fixes: nodejs#1100

Fixes: 1100
PR-URL: nodejs#2609
Reviewed-By: brendanashworth - Brendan Ashworth <[email protected]>
Reviewed-By: jbergstroem - Johan Bergström <[email protected]>

2015-09-02 io.js v3.3.0 Release

2015-08-25 io.js v3.2.0 Release

2015-08-19 io.js v3.1.0 Release

2015-08-04 io.js v3.0.0 Release

2015-08-03 io.js v3.0.0 RC 7

2015-07-30 io.js v3.0.0 RC 6

2015-07-28 io.js v2.5.0 Release

2015-07-24 io.js v3.0.0 RC 5

2015-07-22 io.js v3.0.0 RC 4