One remark: I reached out to the snappy guys since currently the MP wouldn't work for all models. There's a really strange inconsistency with the model names for core 18, i.e.: all 18 model names are prefixed with ubuntu-core-18- now but have the same name basically, so ubuntu-core-18-pi3 etc. But for pc-amd64 and pc-i386 the model names suddenly changed to ubuntu-core-18-amd64 and ubuntu-core-18-i386. We'd have to special-case those if those changes are expected, but to me this is completely unnecessary and stupid.
So this is now good for review.
One remark: I reached out to the snappy guys since currently the MP wouldn't work for all models. There's a really strange inconsistency with the model names for core 18, i.e.: all 18 model names are prefixed with ubuntu-core-18- now but have the same name basically, so ubuntu-core-18-pi3 etc. But for pc-amd64 and pc-i386 the model names suddenly changed to ubuntu- core-18- amd64 and ubuntu- core-18- i386. We'd have to special-case those if those changes are expected, but to me this is completely unnecessary and stupid.
But besides that, please review.