With recent NPM/sandcastle versions, production mode and its additional
optimizations don't fit any more into the 768 MB RAM of sandcastle
containers. Build in development mode, which skips the optimization
steps.
Taken from 7000b4460e
Teach `make dist-gzip` to print the tarball name as last line, and use
it as `create-archive` action.
Add a `make print-version` command which packit can use. The builtin
default only works if there is at least one git tag, which is not the
case for starter-kit (which is never released).
