Update exclusion of registry to include Server 2012R2 (#253)

* Switch to registry based verification

Except for Server 2008 which doesn't use registry to store status, this will resolve issues with attempting to activate windows when English is not the system display language.

* Consolidate to a single guaranteed return

More optimal given a single guaranteed return

* Update catch behavior for failed license lookup

Log the message rather than set $active which is already false

* Update note on Server version

Reflect previous change

sysprep/activate_instance.ps1

@@ -267,7 +267,7 @@ function Verify-ActivationStatus {
   [String]$status = $null
 
   # Server 2008 doesn't store activation status in registry; check slmgr
-  if([Environment]::OSVersion.Version.Major -eq 6 -and [Environment]::OSVersion.Version.Minor -le 1)
+  if([Environment]::OSVersion.Version.Major -eq 6 -and [Environment]::OSVersion.Version.Minor -le 3)
   {
     try {
       $slmgr_status = & cscript //E:VBScript //nologo $env:windir\system32\slmgr.vbs /dli
@@ -281,7 +281,7 @@ function Verify-ActivationStatus {
       $active = $true
     }
   }
-  # All server versions newer than 2008
+  # All server versions newer than 2012R2
   else {
     try {
       $activation_status = (Get-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SoftwareProtectionPlatform\Activation" -Name ProductActivationResult).ProductActivationResult