Update (2012-05-22): Google Apps Scripts now supports libraries: http://googleappsdeveloper.blogspot.com/2012/05/introducing-versions-and-libraries-in.html htt

Update (2012-05-22): Google Apps Scripts now supports libraries: http://googleappsdeveloper.blogspot.com/2012/05/introducing-versions-and-libraries-in.html http://googleappsdeveloper.blogspot.com/2012/05/introducing-... Yay!