Added recipe to handle mounting shared device

I thought it was silly to expect "vms_shared_path" to be setup before hand.
I had this setup for our previous essex site, and just copied the recipe over to this repo.
Simply setting the attributes for shared_device and shared_value in a role or environment suffices. My 'gridcentric-compute.json' file includes vms::compute and vms::nfs and has worked nicely.