Libvirt provider

Adding Packer Qemu builder:
* Packer/answer_files/*_virtio: Install the virtio drivers from the ISO (NOT provided)
* windows_*.json needs some manual tweaks to match the virtio drivers ISO path

Adding Vagrant-libvirt provider:
* Uses the QEMU qcow2 images provided by packer to build the DetectionLab
* Vagrantfile needs manual tweaking to match libvirt's host configuration (backing store, network interfaces, etc)

README:
* Added separate README with instructions for libvirt

Packer/windows_10.json

@@ -1,5 +1,49 @@
 {
   "builders": [
+	  {
+      "type": "qemu",
+      "vm_name":"windows_10",
+      "communicator": "winrm",
+      "iso_url": "{{user `iso_url`}}",
+      "iso_checksum_type": "{{user `iso_checksum_type`}}",
+      "iso_checksum": "{{user `iso_checksum`}}",
+      "headless": true,
+      "boot_wait": "6m",
+      "boot_command": "",
+      "winrm_username": "vagrant",
+      "winrm_password": "vagrant",
+      "winrm_timeout": "4h",
+      "shutdown_timeout": "2h",
+      "shutdown_command": "a:/sysprep.bat",
+
+      "accelerator": "kvm",
+      "disk_size": "{{user `disk_size`}}",
+
+      "output_directory": "{{ user `packer_build_dir`}}",
+
+      "qemuargs": [
+	[ "-m", "2048"],
+	[ "-smp", "2"],
+        [ "-drive", "file={{ user `virtio_win_iso` }},media=cdrom,index=3" ],
+	[ "-drive", "file={{ user `packer_build_dir`}}/{{ .Name }},if=virtio,cache=writeback,discard=ignore,format=qcow2,index=1" ]
+	],
+
+      "floppy_files": [
+        "{{user `autounattend_virtio`}}",
+        "./floppy/WindowsPowershell.lnk",
+        "./floppy/PinTo10.exe",
+        "./scripts/fixnetwork.ps1",
+        "./scripts/rearm-windows.ps1",
+        "./scripts/disable-screensaver.ps1",
+        "./scripts/disable-winrm.ps1",
+        "./scripts/enable-winrm.ps1",
+        "./scripts/microsoft-updates.bat",
+        "./scripts/win-updates.ps1",
+        "./scripts/unattend.xml",
+        "./scripts/sysprep.bat"
+      ]
+
+	  },
     {
       "type": "vmware-iso",
       "vm_name":"windows_10",
@@ -141,6 +185,11 @@
     "iso_checksum_type": "sha256",
     "iso_url": "https://software-download.microsoft.com/download/pr/18362.30.190401-1528.19h1_release_svc_refresh_CLIENTENTERPRISEEVAL_OEMRET_x64FRE_en-us.iso",
     "autounattend": "./answer_files/10/Autounattend.xml",
-    "disk_size": "61440"
+    "disk_size": "61440",
+    "virtio_win_iso": "./virtio-win.iso",
+    "autounattend_virtio": "./answer_files/10_virtio/Autounattend.xml",
+    "packer_build_dir": "/media/packer_build_dir/win10"
+  }
+}
   }
 }