Update template to utilize salt-master locally along with gitfs based salt-formulas

As discussed this is a pull request that sets up the master template to deploy & configure a local salt-master on the Vagrant instance that is setup to utilize the salt formulas:

* https://github.com/saltstack-formulas
* http://docs.saltstack.com/topics/conventions/formulas.html

No changes were required to stackstrap since the `template` object is already available in the context it means that I can grab what I need directly from it. (I will start a new branch on stackstrap to implement the extra context data feature we discussed, but it's now 100% separate from this one).