add a few test things for .net48 target

runprebuild19.bat

@@ -0,0 +1,39 @@
+@echo OFF
+
+bin\Prebuild.exe /target vs2019 /file prebuild48.xml
+
+setlocal ENABLEEXTENSIONS
+set VALUE_NAME=MSBuildToolsPath
+
+if "%PROCESSOR_ARCHITECTURE%"=="x86" set PROGRAMS=%ProgramFiles%
+if defined ProgramFiles(x86) set PROGRAMS=%ProgramFiles(x86)%
+
+rem Try to find VS2019
+for %%e in (Enterprise Professional Community) do (
+    if exist "%PROGRAMS%\Microsoft Visual Studio\2019\%%e\MSBuild\Current\Bin\MSBuild.exe" (
+
+        set ValueValue="%PROGRAMS%\Microsoft Visual Studio\2019\%%e\MSBuild\Current\Bin\MSBuild"
+		goto :found
+    )
+)
+
+
+@echo msbuild for at least VS2019 not found, please install a (Community) edition of VS2019
+@echo Not creating compile.bat
+if exist "compile.bat" (
+	del compile.bat
+	)
+goto :done
+
+:found
+    @echo Found msbuild at %ValueValue%
+    @echo Creating compile.bat
+rem To compile in debug mode
+    @echo %ValueValue% opensim.sln > compile.bat
+rem To compile in release mode comment line (add rem to start) above and uncomment next (remove rem)
+rem @echo %ValueValue% /P:Config=Release opensim.sln > compile.bat
+:done
+if exist "bin\addin-db-002" (
+	del /F/Q/S bin\addin-db-002 > NUL
+	rmdir /Q/S bin\addin-db-002
+	)

runprebuild19.sh

@@ -0,0 +1,26 @@
+#!/bin/sh
+
+case "$1" in
+
+  'clean')
+
+    mono bin/Prebuild.exe /clean
+
+  ;;
+
+
+  'autoclean')
+
+    echo y|mono bin/Prebuild.exe /clean
+
+  ;;
+
+
+
+  *)
+
+    mono bin/Prebuild.exe /target vs2019 /file prebuild48.xml
+
+  ;;
+
+esac