Refactor with some new features

* Split out vagrant commonalities into a vagrant_base class
* Add support for vagrant-vmware_fusion
* Fix vagrant so we log in as root, not log in as vagrant and sudo
* Break out steps in providers: launch, connect, configure
* Generalise the SSH connection routines
* Provide a series of global configuration steps, like ntp sync, hostname
  fixups etc.
* Deprecated the internal_helpers module, its better to avoid global
  methods anyway
* Switched to using RS_ as the prefix for environment variables

Signed-off-by: Ken Barber <ken@bob.sh>