Moved Autounattend.xml's FirstLogonCommands from .xml files to .bat files

Changlog:

- All `Autounattend.xml`s: Replaced `SynchronousCommand`s with `00-run-all-scripts.cmd` which runs all `*.bat` and `*.cmd`s found on floppy.
- All windows templates: Moved keys for consistency across templates (`disk_size`, `guest_additions_path`, `tools_upload_flavor`, `ssh_wait_timeout`
- All windows templates: Changed `--` to `-` in post-processor `output` keys, where found

This provides us numerous benefits:

- Allows us to define the scripts to be run in the templates, instead of the .xml file
- Allows us to easily log the output of the batch files
- Allows us to easily add better error handling/reporting, if we want
- Allows us to have a single configuration script, that sets the parameters to be used by all following scripts, if we want
- Allows us to have a single `Autounattend.xml`, that multiple templates use, for example, we could add a new template to support WinRM, per https://github.com/joefitzgerald/packer-windows/blob/master/answer_files/2012/Autounattend.xml