[Chef] Rename chef.properties into chef-service.properties
Use a relative path for cucumber tests (absolut path is meaningless)
Update license text (2012 -> 2013)
Replace env variable 'PUBLIC_IP' by the relevant call to the context.
Replace env variable 'PRIVATE_IP' by the relevant call to the context.
Add 'return null' at the end of the start closure to mute a warning
Rename the git-type 'tar' into 'tgz' (because it is GZIPed).
Use cp with 'force' option.
Insure consistent behavior when inner_path is unset.
Take all roles (rb, json and js).
Add 'protected' flag on internal stuffs to improve the readability.
Reorder methods to improve the readability.
Merge overloads of runClient thanks to argument with default value.
Merge overloads of runSolo thanks to argument with default value.
Now runList can be given as a properties (then it is added into run_list if it is not alrady included)

Use 'force' option with copy.
Fix runClient and runSolo calls (new signatures).
Don't force to get a chefServerUrl (it can be provided later if we don't use a chef-server deployed by Cloudify).
Save and restaure runParams and chefUrl into the context (if a configuration is updated by a custom command, we must keep it after a self-healing).
Add 'rerun' custom command, it can be used directly or recursively by another custom command that update the configuration (runParams).