Fix up security group crawler and healthcheck ready for redundant prism

In order to put prism behind a load balancer it needed to have a suitable healthcheck and also startup quickly. 

The security group crawling on OpenStack was fairly broken due to jClouds and took up to six minutes to crawl a tenant. This wasn't really acceptable and would mean a deploy would take over 12 minutes. The crawler has been re-written to no longer use the abstraction that jClouds provides and instead uses the underlying Nova Api in jClouds and does the translation itself.

As part of this work the origin object is now attached to each result returned in the Prism API - this needs more work to include things like the tenant ID in openstack and account number for AWS, but it is a great starting point.