pathoGen: Support multiprocess on OS X
pathoGen: Support multiprocess on OS X

In OS X if we create the Couchbase object before forking, then
libevent fails (and python crashes) with the following error:

    [warn] kevent: Bad file descriptor

Fix this by deferring the connection until the child processes have
been created.

Change-Id: Ie0f21c815645959bb23865f0b514ec967977e56f
Reviewed-on: http://review.couchbase.org/43900
Tested-by: buildbot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: thomas anderson <faa2c0189873991686fbb8a0db4c162f340af90c@gmail.com>
Tested-by: thomas anderson <faa2c0189873991686fbb8a0db4c162f340af90c@gmail.com>
Reviewed-by: Venu Uppalapati <5c73d43f38c8de2bc4a2e4d15365e52f60b59dae@gmail.com>
Tested-by: Venu Uppalapati <5c73d43f38c8de2bc4a2e4d15365e52f60b59dae@gmail.com>

thomas-couchbase/perfrunner,couchbase/perfrunner,EricACooper/perfrunner,hsharsha/perfrunner,couchbase/perfrunner,couchbase/perfrunner,EricACooper/perfrunner,pavel-paulau/perfrunner,hsharsha/perfrunner,mikewied/perfrunner,dkao-cb/perfrunner,pavel-paulau/perfrunner,PaintScratcher/perfrunner,vmx/perfrunner,dkao-cb/perfrunner,couchbase/perfrunner,EricACooper/perfrunner,couchbase/perfrunner,thomas-couchbase/perfrunner,mikewied/perfrunner,PaintScratcher/perfrunner,couchbase/perfrunner,pavel-paulau/perfrunner,pavel-paulau/perfrunner,vmx/perfrunner,pavel-paulau/perfrunner,EricACooper/perfrunner