Removed installing net48 in appveyor, added way to have build output on

non-windows systems be the same as on windows.

appveyor.yml

@@ -28,22 +28,6 @@ install:
 
     Write-Host "Installed" -ForegroundColor Green
 
-    Write-Host "Installing .NET Framework 4.8 Targeting Pack..." -ForegroundColor Cyan
-
-    Write-Host "Downloading..."
-
-    $exePath = "$env:TEMP\ndp48-devpack-enu.exe"
-
-    (New-Object Net.WebClient).DownloadFile('https://download.visualstudio.microsoft.com/download/pr/9854b5f2-2341-4136-ad7d-1d881ab8d603/e3a011f2a41a59b086f78d64e1c7a3fc/ndp48-devpack-enu.exe', $exePath)
-
-    Write-Host "Installing..."
-
-    cmd /c start /wait "$exePath" /quiet /norestart
-
-    del $exePath
-
-    Write-Host "Installed" -ForegroundColor Green
-
     }
 before_build:
 - ps: nuget restore

zlib.managed.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp2.0;netcoreapp2.1;netcoreapp2.2;netcoreapp3.0;netcoreapp3.1;netstandard2.0;net40;net45;net451;net452;net46;net461;net462;net47;net471;net472</TargetFrameworks>
+    <TargetFrameworks>netcoreapp2.0;netcoreapp2.1;netcoreapp2.2;netcoreapp3.0;netcoreapp3.1;netstandard2.0;net40;net45;net451;net452;net46;net461;net462;net47;net471;net472;net48</TargetFrameworks>
     <AssemblyName>zlib.managed</AssemblyName>
     <LangVersion>latest</LangVersion>
     <Company>Els_kom org.</Company>
@@ -67,6 +67,7 @@
     <PackageReference Include="System.Runtime" Condition="!$(TargetFramework.StartsWith('net4'))" Version="4.3.1" />
     <PackageReference Include="System.Runtime.Extensions" Condition="!$(TargetFramework.StartsWith('net4'))" Version="4.3.1" />
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.0-beta-20217-01" PrivateAssets="All" />
+    <PackageReference Condition="!$(TargetFramework.StartsWith('netcoreapp')) AND !$(TargetFramework.StartsWith('netstandard'))" Include="Microsoft.NETFramework.ReferenceAssemblies" Version="1.0.0" PrivateAssets="All" IncludeAssets="runtime; build; native; contentfiles; analyzers" />
   </ItemGroup>
 
   <ItemGroup Condition="Exists('..\GitInformation\src\GitInformation\AraHaan.GitInformation.csproj')">