Support absolute paths in 'template' host variable

If the 'template' variable contains a forward-slash (like "Delivery/Quality Assurance/Templates/vCloud/ubuntu-1204-x86_64" rather than just "ubuntu-1204-x86_64"), the harness will search the specified path for a matching VM.

Variables without a forward-slash will continue to search the entire cluster, returning the first matched VM.

This has been tested on staging Jenkins with a template previously failing due to duplicate naming: http://jenkins-staging.delivery.puppetlabs.net/job/vCloud%20test%20-%20Ubuntu/label=acc-coord,os=ubuntu-1204-x86_64/35/console