Use "window" instead of "this"

[jonespen]

I'm trying to load snapper using webpack and babel-loader, but it seems that babel transpiles this to undefined (ref webpack/imports-loader#23, http://stackoverflow.com/questions/34973442/how-to-stop-babel-from-transpiling-this-to-undefined)

It seems like w always refers to the window object, so it should be safe to replace this with window.

Also added some npm script aliases for the grunt tasks