Check if modifyvm.name is set before use the hostname as vm name.
This way one can use different values for hostname and vm name

Previously even if the modify.vm value was set the hostname was subscribing this value
Implement Changes on Other Providers
Merge branch 'fix_vm_name_issue' of https://github.com/pauloelr/Puphpet into pauloelr-fix_vm_name_issue
Adds "override" key to do loop. #1034