Adding a utility method for adding host entries

As much as this is a infrastructure-smell in the linux world, adding
hosts entries is still all to common in the windows world. This method
allows host entries to be configured to meet that need.

It can also be used when developing with vagrant to make sure that the
master and agent vms can see each other properly.
The else case here should just log "nothing to do for this platform" - since it is now win only.