update to GCE.* for enhanced google IOException handling.
Merge pull request #110 from unwin/develop

Fix for listeners and changed load balancer health checks to HTTP from
Merge pull request #108 from unwin/develop-ExceptionEnhancment

update to GCE.* for enhanced google IOException handling.
Fix for one off error in listeners.
removeLoadBalancerHealthCheck - delete a healthCheck using passed in
healthCheckId
detatchHealthCheck - detatch named health check from named loadbalancer.