Remove naming convention limitations

This issue relates to the resource naming convention in a few of the templates like:

- deploymentmanager-samples/community/network/network.py
- deploymentmanager-samples/examples/v2/single_vm/python/vm_template.py

The above list is not exhaustive but illustrative.

The python templates will use a naming convention that will link an attribute to a project name (in network, region and project name for subnets or in vm 'datadisk-'+ context.env['deployment']).

This convention, while useful in quickly spinning up a template, breaks when a user wants to experiment with the templates and add an additional resource of the same type - Deployment Manager will error out when they attempt to create the same resource again.

If a user attempts to kick the tires of the Deployment Manager via these samples, they will quickly hit a road block if they want to see how they add additional resources once they have had one - they'll need to discover how to re-write a .py template file to achieve their goal, if they are patient enough to diagnose that the .py template was the cause.