Normalize line endings
Fixing Windows 7 templates so they work again after the transition to
vagrant-windows.  Windows 7 does not respect the network adapter location
in Sysprep and WinRM requires a non-default location setting to work.
Modified the templates to set the network location manually and refactored
the WinRM install out of Autounattend.xml for easier debugging.
Adding support for PROVISIONER & PROVISIONER_VERSION to Makefile
Adding script to optionally uninstall cygwin on Windows 7 after provisioning
with packer.  Also parametized the shutdown_command parameter in all the
Windows 7 template files (to make this optional).
Better .gitattributes defaults for Windows folks
Normalize line endings after .gitattributes change
Supporting 10.7
Clarify OS X versions and paths to AutoPartition.app
There are two vmware builders in Packer 0.5.x
Adding saltstack as a provisioner option
Fixing Windows VirtualBox vagrant templates for Packer 0.5.x
After Packer 0.5.x was released, running `vagrant up` on VirtualBox
produced the following error:

   ERROR vagrant: #<Vagrant::Errors::VBoxManageError: There was an error while executing `VBoxManage`, a CLI used by Vagrant
    for controlling VirtualBox. The command and stderr is shown below.

    Command: ["modifyvm", "0ae9250c-75b8-43ed-80d7-59e12f6d2c5a", "--macaddress1", "{{ .BaseMacAddress }}"]

    Stderr: VBoxManage: error: Invalid MAC address format

It turns out that with Packer 0.5.x the
`config.vm.base_mac = "{{.BaseMacAddress }}" is no longer required, and if
it is present you must run `vagrant up` twice to get the VirtualBox baseboxes
to work (though it has no adverse effect on VMware).

Though, in order to not break the VMware templates by omitting the
BaseMacAddress, you must supply the appropriate scsi adapter driver
for Packer 0.5.x.

This commit contains both fixes.
Since vagrant-omnibus does not work on Windows, setting the default
provisioner on Windows to be Chef (which can be overridden if this is
not to your liking)