JCLOUDS-788 Added new method to support the passing of a custom node nam...

...e when generating the chef bootstrap node script
Just FTR, I've had a look at the docs for the `client.rb` file (which is the one that configures the node being created, and I've only found the *nodeName* attribute to be node-specific. All other attributes seem to make sense being "global to a group".
If it turns that other attributes are relevant only to a single node, then the signature should be changed to accept a `NodeOptions` or similar class instead of the String. For the moment, I think it is ok as-is.