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

Vagrant/scripts/fix-second-network.ps1

@@ -1,10 +1,32 @@
 # Source: https://github.com/StefanScherer/adfs2
-param ([String] $ip, [String] $dns)
+param ([String] $ip, [String] $dns, [String] $gateway)
 
-if (! (Test-Path 'C:\Program Files\VMware\VMware Tools')) {
+if ( (Get-NetAdapter | Select-Object -First 1 | Select-Object -ExpandProperty InterfaceDescription).Contains('Red Hat VirtIO')) {
+  Write-Host "Setting Network Configuration for LibVirt interface"
+  $subnet = $ip -replace "\.\d+$", ""
+  $name = (Get-NetIPAddress -AddressFamily IPv4 `
+     | Where-Object -FilterScript { ($_.IPAddress).StartsWith("$subnet") } `
+     ).InterfaceAlias
+  if ($name) {
+    Write-Host "Set IP address to $ip of interface $name"
+    & netsh.exe int ip set address "$name" static $ip 255.255.255.0 "$gateway"
+    if ($dns) {
+      Write-Host "Set DNS server address to $dns of interface $name"
+      & netsh.exe interface ipv4 add dnsserver "$name" address=$dns index=1
+    }
+  } else {
+    Write-Error "Could not find a interface with subnet $subnet.xx"
+  }
+  
+  exit 0
+}
+
+if (! (Test-Path 'C:\Program Files\VMware\VMware Tools') ) {
   Write-Host "Nothing to do for other providers than VMware."
   exit 0
 }
+
+
 Write-Host "$('[{0:HH:mm}]' -f (Get-Date))"
 Write-Host "Setting IP address and DNS information for the Ethernet1 interface"
 Write-Host "If this step times out, it's because vagrant is connecting to the VM on the wrong interface"