Add a script to build all samples

build-dir.cmd

@@ -0,0 +1,25 @@
+@echo off
+setlocal
+set logfile=%cd%\build-result.log
+del %logfile% 2>nul
+call :check_folder . .
+goto :eof
+
+rem =========================================
+rem check_folder
+rem   $1 - sub-folder name
+rem   $2 - full path to the sub-folder
+rem
+:check_folder
+pushd %1
+if exist *.sln (
+    echo %2
+    echo === %2 >> %logfile%
+
+    for /f %%i in ('dir /b *.sln') do (
+        msbuild /nologo /v:q /m /t:rebuild %%i >> %logfile%
+    )
+) else (
+    for /f %%i in ('dir /b /ad') do call :check_folder %%i %2/%%i
+)
+popd