U4-10006 - use Invoke-WebRequest, misc

build/Modules/Umbraco.Build/Build-UmbracoDocs.ps1

@@ -104,8 +104,7 @@ function Get-DocFx($uenv, $buildTemp)
   {
     Write-Host "Download DocFx..."
     $source = "https://github.com/dotnet/docfx/releases/download/v2.19.2/docfx.zip"
-    $client = new-object Net.WebClient
-    $client.DownloadFile($source, "$buildTemp\docfx.zip")
+    Invoke-WebRequest $source -OutFile "$buildTemp\docfx.zip"
     
     &$uenv.Zip x "$buildTemp\docfx.zip" -o"$buildTemp\docfx" -aos > $nul
     Remove-File "$buildTemp\docfx.zip"  

build/Modules/Umbraco.Build/Get-UmbracoBuildEnv.ps1

@@ -14,7 +14,7 @@ function Get-UmbracoBuildEnv
   {
     mkdir $path > $null
   }
-  
+
   # ensure we have NuGet
   $nuget = "$path\nuget.exe"
   $source = "https://dist.nuget.org/win-x86-commandline/latest/nuget.exe"
@@ -25,8 +25,7 @@ function Get-UmbracoBuildEnv
   if (-not (test-path $nuget))
   {
     Write-Host "Download NuGet..."
-    $client = new-object Net.WebClient
-    $client.DownloadFile($source, $nuget)
+    Invoke-WebRequest $source -OutFile $nuget
   }
   
   # ensure we have 7-Zip
@@ -98,8 +97,7 @@ function Get-UmbracoBuildEnv
   if (-not (test-path $node))
   {
     Write-Host "Download Node..."
-    $client = new-object Net.WebClient
-    $client.DownloadFile($source, "$path\node-v6.9.1-win-x86.7z")
+    Invoke-WebRequest $source -OutFile "$path\node-v6.9.1-win-x86.7z"
     &$sevenZip x "$path\node-v6.9.1-win-x86.7z" -o"$path" -aos > $nul
     Remove-File "$path\node-v6.9.1-win-x86.7z"    
   }

build/Modules/Umbraco.Build/Verify-NuGet.ps1

@@ -357,7 +357,19 @@ function Verify-NuGet
     $uenv.Semver
   )
   
-  add-type -referencedAssemblies $assem -typeDefinition $source -language CSharp
+  try
+  {
+    # as long as the code hasn't changed it's fine to re-add, but if the code
+    # has changed this will throw - better warn the dev that we have an issue
+    add-type -referencedAssemblies $assem -typeDefinition $source -language CSharp
+  }
+  catch
+  {
+    if ($_.FullyQualifiedErrorId.StartsWith("TYPE_ALREADY_EXISTS,"))
+      { Write-Error "Failed to add type, did you change the code?" }
+    else
+      { Write-Error $_ }
+  }
   if (-not $?) { break }
   
   $nuspecs = (