IMPR: Now the size of a new disk is specified in MB instead GB as wished in https://github.com/hashicorp/vagrant/pull/6321#issuecomment-179687930.
MISC: Got this working on creating a new machine. Seems to be problems when halting and up'ing the machine again. It says it can't attach the disk again. Perhaps it was better having this code in import_vm.ps1 anyway?
MISC: Lots of puts for debug purposes.