Code review comment for ~paul-meyer/cloud-init:fix-ntfs-mount

> I'd prefer if we detected that we can't mount ntfs by checking for
>
> a) is there an ntfs kernel module
> b) is there a mount.ntfs tool in $PATH
These checks are implemented now.

> It was also mentioned that images which don't support ntfs, could embed cloud-
> config, like:
>
> "support_ntfs: false"
>
> That could also be metadata that the AzureDataSource uses to determine if the
> mount failure is fatal or not.
We don't need this right now, so I left it out.