Rename current examples as demos as it's more what they are about. Ensure that CI still runs when growing a new "demos" argument and keep examples backward compatibility until we introduce real examples as getting started guide. For now, we keep the snapcraft-examples package. I think this package can ship both demos and examples. This is the base work for the new "snapcraft-examples" command which will scaffold the getting started examples we work together on. I feel we may have to push this command (and so examples) as part of the main package though (and so, can introduce confusion with the existing package name). Note that I kept backward compatibility for CI. I couldn't run the whole CI testsuite though as it requires some 15.04 snappy/u-d-f and will rely on the current automated CI test results then :)