Adding a script to capture the commands I used to build WinSparkle. N…

…ote this is not used, as I still build with the binary release. The WinSparkle repository is here for debugging.

third_party/build_winsparkle.bat

@@ -0,0 +1,13 @@
+cd winsparkle
+
+rem Download nuget if required
+wget https://dist.nuget.org/win-x86-commandline/v5.7.0/nuget.exe
+
+rem Need to have nuget on the path
+nuget install packages.config -OutputDirectory packages
+
+rem Then run msbuild, need Command Line for Visual Studio for this to work
+msbuild WinSparkle-2017.sln /t:Build /p:Configuration=Debug;WindowsTargetPlatformVersion=10.0.18362.0;Platform=x64
+
+rem Problem is to specify the exact same Windows SDK version as you have (is a CMake output). Could also use the outer property when called from a solution,
+rem but how to nest solutions?