build windows installers

[starpit]

there is work in starpit/fix_999; to be useful, this will require the use of a nuget repo

https://github.com/starpit/shell/tree/fix_999

in particular squirrel.js and msi.js in https://github.com/starpit/shell/tree/fix_999/dist/builders

[starpit]

that fork/branch also builds an MSI, though this will require the use of appveyor or some other form of windows build machine, as the msi builder depends on the wix toolset http://wixtoolset.org/ which only runs on windows