Update GitFS Backend Walkthrough to include GitFS over SSH 

A small description on how to configure GitFS over SSH transport.
Make pkg.install respect __env__

This fixes #5209.
Add 'vmadm' module which provides 'virt' for SmartOS

First commit of 'smartos_vmadm', a module that uses the 'vmadm'
command on SmartOS CN. For the moment very few functions are present
but I'm pretty sure that more will come in a couple of days.

Implemented :

* list_vms()

* list_active_vms()

* list_inactive_vms()

* shutdown(uuid)

* start(uuid)

* reboot(uuid)
Merge pull request #5248 from virtua-network/smartos_vmadm

Add 'vmadm' module which provides 'virt' for SmartOS
Merge pull request #5247 from terminalmage/issue5209

Make pkg.install respect __env__
Merge pull request #5244 from valentinbud/develop

Update GitFS Backend Walkthrough to include GitFS over SSH
Allow slashes in gitfs envs, Fix #5007
Add docstring to interface()
Merge pull request #5251 from UtahDave/new_win_network

Add docstring to interface()
be consistent about .override use

disabling of service is correct, but checking whether
it is disabled is not

upstart service is disabled by creating {service-name}.override file
and adding a 'manual' stanza there [1]

[1] http://upstart.ubuntu.com/cookbook/#disabling-a-job-from-automatically-starting
Add new ref logic to _get_ref as well
Merge pull request #5252 from kvbik/disabling-upstart-job

be consistent about .override use
Merge pull request #5253 from basepi/gitfs5007

Allow slashes in gitfs envs, Fix #5007
Parse kwargs with YAML, Fix #5224
Merge pull request #5256 from basepi/yamlargs5224

Parse kwargs with YAML, Fix #5224