Don't build rsync on windows

This gets the project to the point of actually attempting to build an MSI:
https://gist.github.com/schisamo/ab756193354e33347307

I'm about to deploy the [associated opscode-ci code](https://github.com/opscode-cookbooks/opscode-ci/commit/2cb92070e952cf3a19e9a073cf8b7995901bcf75) that will allow Windows nodes to build projects not named `<PROJECT>-windows`.