Add startEventLoop(int nthreads)

Change-Id: I7f013b068b333d7ac0ab535b24adc48298ca4390
Reviewed-on: http://gerrit.aldebaran.lan/37173
Reviewed-by: pdaouadi <pdaouadi@aldebaran-robotics.com>
Tested-by: pdaouadi <pdaouadi@aldebaran-robotics.com>
Merge commit 'refs/integration/team/hotfix/dev-137'