Code submission for IN4308

Hi @guwac,

As you've seen in the email discussion, we've been unable to create an updatesite project that actually builds. We've tried a lot of things, but we think everyone is out of ideas now. Given that @vvergu can create and build an updatesite, we hope this is an OS thing and that you'll be able to do it as easily on your mac. 
We've also made an attempt to upgrade the project too Spoofax 1.3, but we're not sure how to work around issues with on-save handlers not working properly. You can find that work in the upgrade1.3 branch, so if you're interested, you might make a similar branch in your repo and pull our branch to it so that work isn't lost. 

Thanks for the support, and having us work on your project. It was fun and interesting!
@rvanheest, @rmhartog, and @Apanatshka